Experimental Psychology Reviewer.pdf

Experimental Psychology
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Chapter 1
Experimental Psychology and the Scientific Method
Chapter Overview
Researchers obtain knowledge about psychological processes by using scientific methodology. The
alternative, commonsense psychology, utilizes nonscientific sources of data and inference, and is subject to many
kinds of errors. Modern science avoids the errors inherent in commonsense psychology by assuming a natural
order (the scientific mentality). Scientists gather observable data, develop laws or theories to organize and explain
our findings, use good thinking (objective, organized, rational, and parsimonious reasoning), challenge findings
through attempts to falsify–not verify–new hypotheses (self-correction), publicize results, and repeat experimental
procedures to confirm previous findings (replication). Psychologists revise explanations and theories when
required by the weight of evidence.
The four major objectives of psychological research include description, prediction, explanation, and
control. Diverse psychological research methods are used in both applied and basic research. The tools of
psychological science are observation, measurement, and experimentation. Researchers manipulate sets of
antecedents called treatments in a psychology experiment. The minimum requirements for an experiment are that
we must have procedures for manipulating the antecedents and the predicted outcome must be observable. A
psychology experiment is a controlled procedure in which we apply at least two different treatment conditions to
subjects and then measure and compare subject behaviors to test an experimental hypothesis. Scientists use
experiments to infer a cause and effect relationship between treatment conditions and subjects’ behavior.
When psychology joined the discipline of mental philosophy in the 1800s, it contended against the
popular pseudosciences of phrenology, physiognomy, spiritualism, and mesmerism. Contemporary psychology
deals with their modern counterparts, like eye movement desensitization therapy. All of these therapies share the
appearance of being scientific, but they lack a scientific basis and have not been confirmed using the scientific
method.
Psychologists begin the experimental process by reviewing the research literature to generate
hypotheses about behavior, which provides the basis for the Introduction section of a psychological report. We
design a procedure to systematically test that hypothesis, which is described in the Method section. We
statistically analyze our experimental data and report whether or not they support the hypothesis in the Results
section. Finally, we evaluate the meaning of our findings in the context of previous research and re-evaluate our
procedures and hypothesis in the Discussion section
Commonsense Psychology
Our culture is full of psychological conclusions that are more based on commonsense than science. For example,
everyone knows that the “smart kids sit in the front of the class.” Ask students to identify three or four of these
adages. Ask them to describe the nonscientific ways in which these conclusions were made, and identify problems
with these methods. Finally, brainstorm ways to scientifically investigate these sayings. Be sure to point out to your
students that “common sense” and “nonscientific inference” usually involve going straight from observation or
anecdote to conclusion, whereas the scientific method inserts the critical steps of hypothesis/prediction and testing
between observation and conclusion.
Observation
Psychology is sometimes criticized as a “black box” science because it studies processes that go on invisibly
inside the mind. For each of the following invisible mental processes, have students brainstorm ways in which
these blackbox processes can be observed systematically and then quantified. For example, memory can be
measured through a digit span task, a random word list, or a reading comprehension task.
Scientific versus Nonscientific Methodology
One point of Chapter 1 is the weakness of nonscientific inference. Each of the following statements could be
easily evaluated in a nonscientific way, but could also be examined scientifically. Ask students to identify both
nonscientific and scientific ways to evaluate each statement. Have students specify potential problems with the
nonscientific approaches that are identified. Tip: be on the lookout for examples of verification rather than
falsification (see Handout 1-1).
Handout 1-1: Falsification and Verification

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An important, but often neglected, ingredient of scientific investigation is the process of falsification. One reason
falsification is neglected is that the opposite process, verification, is so much easier. For each of the following
hypotheses, identify data that would verify the statement, and data that would falsify it.
Key to Review and Study Questions
1. Why do we need scientific methods?
Science is one of many complementary approaches to studying our universe.
While science is unsuited for questions about the meaning of life or the nature of
God, scientists believe that scientific methods are our best means of
understanding human behavior. Scientific methods help us study psychological
processes in an objective, systematic, and replicable fashion.
2. How can commonsense psychology reduce objectivity when we gather data?
Commonsense psychology is the everyday, nonscientific collection of
psychological data used to understand the social world and guide our behavior.
While commonsense psychology often works adequately in commonplace
situations, like asking your roommate for a ride, it may mislead us in novel
circumstances, like answering personal questions during a job interview.
Commonsense psychology is not able to explain or predict human behavior, in
general, because it is crippled by reliance on nonscientific sources of information
and nonscientific inferential strategies.
3. Give an example of how you used commonsense psychology in the past week.
Students may cite diverse examples including judging the difficulty of an upcoming
test by the professor’s tone of voice and how to select compatible roommates.
4. What are the characteristics of modern science?
As scientists, we assume Alfred North Whitehead’s scientific mentality and believe
that the universe is orderly and that the scientific method can discover its laws. We
use good thinking, which is systematic, objective, and rational data collection and
interpretation. Good thinking uses logical and parsimonious reasoning.
We systematically collect empirical (observable) data using three main tools:
observation, measurement, and experimentation. We frame testable hypotheses
and design procedures, like experiments, to falsify them. We build general
principles from specific observations to explain our findings and then generate new
predictions from these principles.
Modern science is self-correcting since we appreciate the uncertainty of our
findings. The content of science changes as we acquire new information and
reevaluate previous data. We revise or replace theories as the weight of
evidence shifts.
Scientists publicize results through presentations at professional meetings, in
scientific journals, and on the internet. This disseminates research findings and
reduces unintended duplication of effort.
Lastly, modern science is characterized by replication, which is the process of
repeating research procedures to confirm that the outcome will be the same as
before. Successful replication increases our confidence in the robustness of
research findings. Replication failures can help us identify the boundary conditions
within which a phenomenon occurs.
5. What do we mean by objectivity? How does objectivity influence observation,
measurement, and experimentation?

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Objectivity means that our use of the scientific method is not biased by personal
beliefs or expectations.
Objectivity keeps a scientist “honest” during every aspect of the scientific method:
reviewing prior studies, selecting a question for study, framing a hypothesis,
designing an experiment, running an experiment, obtaining data, statistically
analyzing data, interpreting data, and explaining the meaning of our results in the
context of previous studies. Failure to maintain objectivity at any stage could result
in false conclusions.
6. Suppose that a researcher believed that firstborn children have higher IQs than
their later born sisters and brothers because the mother’s ova are younger
when firstborns are conceived. This hypothesis would not be testable. Explain why
not.
First, there is no noninvasive method of measuring the age of an ovum when it is
fertilized. Second, there is no ethical way to manipulate the age at which an ovum
is fertilized.
7. How does a psychology experiment demonstrate a cause and effect relationship
between antecedent conditions and behavior?
Antecedent conditions (treatments) are the circumstances that come before an
event or behavior we wish to explain. An experiment is a controlled procedure in
which we apply at least two different antecedent conditions to our subjects and
measure their effects on behavior.
An experiment must satisfy two requirements: we must have procedures for
manipulating the setting and we must be able to observe the predicted outcome.
After we administer the treatments, we measure and compare subject performance
across conditions to test the experimental hypothesis.
8. What do we mean by treatment conditions in an experiment? Why must there be at
least two?
Treatment conditions are specific sets of antecedent conditions that an
experimenter applies to experimental subjects. A minimum of two treatment
conditions allows us to compare behavior under different treatments to control for
the effects of variables outside an experimenter’s control. For example, if subjects
receiving a new anti-depressant drug improve after three months, we cannot rule
out the contribution of the placebo effect, changes in other people’s expectations
and behavior toward them, and changes in their lifestyle, to their improvement. A
credible second treatment condition allows us to rule out these competing
explanations.
9. For each of the following examples, state at least one of the basic tools of
psychological science (observation, measurement, experimentation) that have
been violated, and explain the correct procedure:
a. Deanna wanted to do an experiment on gas mileage to see whether the name
brands give better mileage. She filled her tank with Fuel-Up one week and with
a well-known brand the following week. At the end of that time, she thought
things over and said, “Well, I didn’t notice much difference between the brands.
I filled the car with Fuel-Up on a Tuesday and needed gas again the following
Tuesday. It was the same story with the big-name brand, so they must be about
the same.”

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Deanna violated the principles of measurement and control. To accurately
measure gas mileage, she should have recorded the exact number of miles
traveled on each tank of gas and the amount of fuel consumed during each
condition. To control the antecedent conditions, she should have ensured that
driving conditions (city or highway) and the way she drove (acceleration, load,
number of passengers, and speed) were identical.
b. Mike has been telling all his friends that his three-year-old daughter, Allie, can
read. One evening Mike invites some of his friends over for coffee and offers to
give a demonstration of his daughter’s remarkable skill. Allie then appears to
read a small storybook that Mike keeps on the coffee table. One of the friends
is not convinced and asks the little girl to read a page from a different but
equally simple storybook. Allie remains silent. Mike explains Allie’s behavior by
saying, “She’s just shy with strangers.”
Mike violated the principles of replication and objectivity. If Allie can actually
read, then she should have been able to read a page from a storybook of
comparable difficulty. Her inability to read this selection constituted a failure in
replication. Mike’s explanation, “She’s just shy with strangers,” showed his lack
of objectivity, since he was unwilling to consider an alternative explanation for
his daughter’s performance (e.g., she memorized his spoken words as he read
the storybook to her).
c. An author advocates the use of large doses of vitamin C to prolong life. In an
interview he says he has tried this treatment only on himself.
The author violated the principles of control and objectivity. To control
antecedent conditions, the author needed to randomly assign subjects with
comparable life expectancies to either vitamin C or control conditions. Since
there was only one treatment condition, we have no way to determine the
length of the author’s life without vitamin C therapy. We should also question
the author’s objectivity if his income were based on sales of books and fees
from lectures advocating this therapy.
d. A researcher wanted to compare the effects of a funny cartoon vs. a violent
cartoon on viewers’ moods. She measured mood by observing the body
language of her subjects. She couldn’t find any systematic differences in mood
for the two treatments.
The researcher violated the principle of measurement since body language
measures only one aspect of mood and is not a primary measurement tool in
research on emotion.
10. Explain why astrology is a pseudoscience rather than a true science.
A pseudoscience lacks a scientific basis and it does not confirm its claims using
the scientific method. Astrology is a pseudoscience because it does not utilize the
scientific method to postulate its assumptions and empirically test its predictions.
There is no objective evidence that testable astrological predictions achieve
greater than chance accuracy.
11. Name and describe each of the four main sections of the experimental report.
The four main sections of the experimental report include the Introduction, Method,
Results, and Discussion. The Introduction section states the research problem and
reviews prior studies in the field. The Method section describes the experimental
design, including the subjects, materials and equipment, and procedure. The
Results section reports the statistical analysis of the experimental data. Lastly, the
Discussion section summarizes, evaluates, and interprets the findings in the
context of the experimental hypothesis and previous studies.

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Chapter 2
Research Ethics
Chapter Overview
Researchers carefully treat subjects who participate in their studies. Federal law regulates several
aspects of psychological research, including the establishment of an institutional review board (IRB) and
institutional animal care and use committee (IACUC).

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An IRB evaluates proposed studies using human participants and determines whether they place
subjects at risk. When a subject is more likely to be harmed by participating in a study than by not participating, an
IRB performs a risk/benefit analysis to determine whether the study is justifiable. Federal statutes strongly
influenced the American Psychological Association’s (1992) Ethical Principles of Psychologists and Code of
Conduct. APA standards for informed consent, full disclosure, deception, debriefing, anonymity, and confidentiality
protect participants’ rights. Participants must be debriefed whenever an experiment involves deception.
An IACUC evaluates proposed studies to ensure that researchers have carefully researched alternatives
to animal research and have decided to use a minimum number of animals. The amended Animal Welfare Act of
1966 and professional organizations, such as the AALAS and AAALAC, have contributed to uniform animal care
standards and self-policing by the scientific community. Researchers must promote animal welfare whenever they
use animal subjects. Despite allegations by critics of animal research, there is little evidence of animal abuse in
psychological research. While some critics advocate animal rights, the position that all species are equally valued
and have equal rights, most people support animal experimentation because of its contribution to human welfare.
Scientific fraud encompasses fabrication and falsification of data, and plagiarism, is unethical, and can
result in severe personal and institutional consequences. There are diverse reasons for scientific fraud. Peer
review, replication, and academic competition help control fraud. Plagiarism, representing someone else’s work as
your own, is a type of fraud. Researchers must credit others who contributed words or ideas to their work through
citations. In ethical reports, those listed as report authors must have made important contributions to the research.
Researchers may only republish previously published data if they cite the original publication where the data first
appeared.
Handout 2-1: Risk/Benefit Analyses
A risk/benefit analysis is fairly easy to understand in theory, but fairly difficult to conduct in practice. Conduct a
risk/benefit analysis on each of the following experiment proposals. Assume you are responsible for deciding
whether or not to approve each experiment. You must justify each decision. Suggest ways to improve each
proposal.
1) Mickey wants to study how food deprivation affects learning in mice. He believes that animals have a survival
instinct to learn more quickly when food is scarce. He proposes an experiment in which mice are given only water
for 1, 2, 5, or 10 days. He then plans to measure the speed with which they learn to navigate a complicated maze.
2) Barbara believes that people will shift from using paper towels to using electric air dryers in public restrooms if
they are told about the amount of paper waste in landfills. She proposes a study in which a sign is posted in some
bathrooms explaining the pollution problem, but is not posted in other bathrooms. She will use hidden
videocameras to record people’s use of either the paper towel dispenser or electric air dryer in each of the two
bathroom conditions.
3) Lucy believes that our self-image affects how we rate the appearance of others. She proposes an experiment in
which participants rate the attractiveness of various models. Unbeknownst to the participants, a confederate will
be loitering in the hallway outside the experiment room. As volunteers arrive for the experiment, the confederate
will either compliment (“you look nice in that outfit”) or insult (“that outfit makes you look fat”) the participant. Lucy
will then compare the model ratings from complimented and insulted participants.

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Handout 2-2: Identifying Ethics Violations
Identify as many ethical violations as you can in the following scenario. Explain each of the violations you find.
Mark decided that participants in this study will not be at risk, and therefore, he didn’t bother the IRB with his
proposal. His study investigates the amount of discomfort people are willing to put up with in order to earn a large
sum of money. He recruits students by posting ads about a “contest in which you can earn $1000.” Everyone who
shows up is told that they must do whatever he tells them to do for the next several hours and that the last person
to comply will earn the money. He then makes the participants eat disgusting food combinations, rub permanent
markers on their own faces, and mail insulting messages to their professors. After two hours he stops the
“contest,” informs everyone that it was actually an experiment, and explains that there is no prize money. Before
participants leave, he gets them to sign an informed consent form to acknowledge that they “were free to leave at
any time.”

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1. Explain why IRBs are necessary and what their major functions are.
An IRB evaluates proposed human research studies before they are conducted.
The main responsibility of an IRB is to protect subject safety. An IRB’s first task is
to determine whether a proposed study places subjects “at risk.” If an IRB decides
that participation in a study will increase the risk of subject injury, it must conduct a
risk/benefit analysis to determine whether risks to individuals are outweighed by
potential benefits or knowledge gained. An IRB also safeguards the rights of
subjects in at risk studies by ensuring that researchers obtain informed consent.
2. What is informed consent?
Informed consent means that a subject agrees to participate following a complete
explanation of the nature and purpose of a study. It is required for all human
research studies. Consent forms must be written in lay language at a reading level
subjects can understand. Researchers should verbally explain information that is
important for subjects. Subjects who agree to participate in a study should sign the
consent form and then receive a copy for their records.
The following aspects of informed consent are important in psychological research:
subjects must give their consent freely
subjects must be free to leave an experiment at any time
researchers must fully explain experimental procedures and answer any
questions about them
researchers must explain potential risks and benefits
researchers must assure subjects that all data will remain private and confidential
subjects may not be asked to release the researchers from liability or to waive their legal rights in the case of
negligence
How is it related to respect for persons in the Belmont Report?
Informed consent derives from the principle of respect for persons contained in the
1979 Department of Health, Education, and Welfare Belmont Report. Respect for
persons means that individuals should be free to make their own decisions about
research participation and that we must provide extra protection for vulnerable
populations and persons with diminished capacity while respecting their
self-determination.
3. When is it appropriate to use deception?
Deception is appropriate when it is an experimenter’s only means of testing an
experimental hypothesis.
When is it not appropriate?
APA Standard 6.15 (b) prohibits deception that would influence a subject’s
decision to participate in the study.
How can the negative effects of deception be eliminated?
We can eliminate the negative effects of deception by thorough debriefing as
required by APA Standard 6.15 (c): “Any other deception that is an integral feature
of the design and conduct of an experiment must be explained to participants as

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early as is feasible, preferably at the conclusion of their participation, but no later
than at the conclusion of the research.”
4. At the end of the semester, all students in a general psychology course are told
they will not receive credit for the course unless they take part in the instructor’s
research project. Students who refuse to participate are given “Incompletes” and
do not get credit for the course. How has the ethical principle of informed consent
been violated?
The instructor’s requirement is unethical because it constitutes coercion and
thereby violates three sections of APA Standard 6.11. The requirement violates
APA standard 6.11 (b) which requires that psychologists “inform participants
that they are free to participate or to decline to participate.” It violates APA
Standard 6.11 (c): “When psychologists conduct research with individuals such
as students or subordinates, psychologists take special care to protect the
prospective participants from adverse consequences of declining or withdrawing
from participation.” Finally, it violates APA Standard 6.11 (d): “When research
participation is a course requirement or opportunity for extra credit, the
prospective participant is given the choice of equitable alternative activities.”
5. An experimenter studying the effects of stress gave subjects a series of maze
problems to solve. The subjects were led to believe that the problems were all
quite easy. In fact, several had no solution. Some of the subjects were visibly upset
by their inability to solve the problems. At the end of the study, the experimenter
did not explain the procedures. What ethical principles apply in this case?
The experimenter violated APA Standard 6.11 (c): “…they inform participants of
significant factors that may be expected to influence their willingness to participate
(such as risks, discomfort, adverse effects, or limitations in confidentiality, except
as provided in Standard 6.15, Deception in Research).” The experimenter violated APA Standard
6.15 (c): “Any other deception that is an integral feature of
the design and conduct of an experiment must be explained to participants as early
as is feasible, preferably at the conclusion of their participation, but no later than at
the conclusion of the research.”
Finally, the experimenter violated APA Standard 6.15 (b): “Psychologists never
deceive research participants about significant aspects that would affect their
willingness to participate, such as physical risks, discomfort, or unpleasant
emotional experiences.”
What should the experimenter have done?
The experimenter should have warned subjects about the difficulty and potential stress of the maze problems, and
should have immediately debriefed them after they completed the study.
6. In a questionnaire study of sexual attitudes, a student experimenter finds that Pat,
a friend’s spouse, has responded yes to the question, “Have you ever had an
extramarital affair?” The student is sure that the friend is unaware of Pat’s
behavior. The student decides to show Pat’s answers to the friend. What ethical
principles have been violated?
The student experimenter failed to maintain anonymity (subject names were on
data sheets) and confidentiality (the security of the data was violated).
How could this situation have been avoided?

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The experimenter should have coded data sheets so that Pat’s answers remained
anonymous. Furthermore, the experimenter should not have shared experimental
data with a friend.
7, What ethical principles apply when we propose and conduct research with
animals?
APA Standard 6.20 outlines the requirements for ethical animal research.
Researchers must protect animal welfare whenever they use animal subjects.
These guidelines concern:
humane treatment of animal subjects
compliance with federal, state, and local laws and regulations, and relevant professional standards
training of all individuals using animals in research methods and in the care, maintenance, and handling of the
species being used
staff competence to fulfill their responsibilities and activities
minimizing the discomfort, infection, illness, and pain of animal subjects
subjecting animals to pain, stress, or privation only when there are no satisfactory alternatives and the animals’
distress is justified by the study’s potential value
use of anesthesia during surgery and techniques to avoid infection and minimize pain
termination of an animal’s life using an accepted, rapid method that minimizes pain
8. What is the difference between animal welfare and animal rights?
Animal welfare is the humane care and treatment of animals, which is regulated by
federal and state statutes and the ethical standards of professional organizations.
Animal rights is the idea that all sensate species, especially those that feel pain,
are of equal value to humans and should have the same subject rights as humans.
9. To study the effect of a new drug to reduce depression, researchers must sacrifice
animal subjects and dissect their brains. Discuss the ethical pros and cons of this
line of research.
APA Standard 6.20 defines the ethical standards for animal research. An
institutional animal care and use committee (IACUC) must first determine that
there are no satisfactory alternatives to animal experimentation and that the
number of animals used in the study has been minimized. An IACUC would
approve the study if it promises to contribute to mental health and follows APA
guidelines for the humane termination of an animal’s life.
This question implies the broader philosophical question of whether animals should
be sacrificed for the sake of human welfare. Students are likely to endorse
divergent positions as they grapple with the issue of animal rights. In this context,
the pros are that animal research is indispensable in psychopharmacological
research, can help save human lives, and can improve depressed patients’ quality
of life. The con is that the lives of members of a sensate species will be sacrificed.
10. What is fraud?
Fraud includes falsifying or fabricating data, and plagiarism.
Describe the external pressures that can produce fraud.
Competition in academic psychology may be a primary cause of fraud.
Researchers frequently compete for tenure, promotion, departmental resources,
and grant funds based on their publication records. The pressure is most intense in
“publish or perish” institutions and for individuals who have experienced a series of
research setbacks.
Describe the safeguards that keep it in check.

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Peer review is the first safeguard since reviewers closely scrutinize submitted
manuscripts and are likely to detect suspect findings. Replication is the second
safeguard, since fraudulent findings are not likely to be replicated. Finally,
academic competition for scarce resources like grants increases vigilance against
fraud by colleagues in a specialty area.
What are the possible penalties for scientific misconduct?
The penalties for scientific misconduct depend on the offense and who determines
guilt and punishment. Penalties imposed by a university could range from a
reprimand to firing, while criminal court penalties could be as severe as
imprisonment. An institution’s reputation could be harmed by a researcher’s
misconduct and it could be forced to return funds or prevented from receiving
future grant funds.
11. Lee had put off doing a lab report until the end of the term. He was badly pressed
for time. His roommate said, “No problem. I took that course last year. You can use
my report. Just put your name on it.” Lee decides it is all right to use the paper
since he has the author’s consent. Is this ethical according to the APA? Why or
why not?
No. Lee committed plagiarism since he misrepresented his roommate’s work as
his own. His roommate’s encouragement only made him complicit in Lee’s
misconduct.
Chapter 3
Alternatives to Experimentation: Nonexperimental Designs
Chapter Overview
Psychologists often prefer the experimental method since it allows us to determine causal relationships
between antecedent conditions and subsequent behavior. However, experiments may achieve internal validity
while sacrificing external validity. Nonexperimental studies are techniques that do not manipulate antecedent
conditions. Approaches like phenomenology, case studies, field studies, archival studies, and qualitative research
may be used when experimentation is not possible or desirable.
The authors discuss the internal and external validity of experimental and nonexperimental approaches.
They describe research methods using a two-dimensional graph of degree of manipulation of antecedent
conditions and degree of imposition of units.
The authors examine four common nonexperimental approaches used by psychologists to study human
and animal behavior: phenomenology, case studies, field studies, archival studies, and qualitative research. They
illustrate how these approaches are used in psychology, describe their basic procedures, and review their
strengths and limitations.
Phenomenology describes an individual’s immediate experience, uses personal experience as the
source of data, and falls near the low-low end of the research activities graph. Phenomenological data are limited
because we cannot make cause and effect statements about our experience, our statements might not be
completely accurate or objective, and our experiences may not be generalizable to others. This technique may
stimulate research, help us formulate hypotheses, and help us study the effects of experimental manipulations.
Case studies provide a descriptive record of a single individual’s experiences, behaviors, or both, kept
by an outside observer. This technique falls near the low-high end of the research activities graph and has been
extensively used by clinical psychology, forensic psychology, and organizational psychology. They are a useful

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source of ideas, can lead to therapy techniques, allow us to study rare phenomena, demonstrate counterinstances,
and can stimulate new research. In clinical psychology, an evaluative case study is used to assess an individual’s
overall level of psychological functioning. A deviant case analysis is an extension of the evaluative case study that
compares deviant and normal individuals for significant differences. While case studies are a useful source of
information, their reliance on retrospective data, data collected in the present based on recollections of past
events, is a serious limitation.
Field studies are nonexperimental approaches used in real-life settings and often combine several data
collection methods. This technique falls anywhere from low-low to the low-high end of the research activities graph.
Field studies include observational studies by ethologists, child development studies, market research, and
organizational studies.
Two types of field studies are naturalistic observation studies and participant-observer studies.
Naturalistic observation is the technique of observing behaviors as they spontaneously occur in natural settings.
This approach reduces subjects’ reactivity and allows us to study behaviors that would be distorted or absent in
the laboratory. A researcher can use systematic observation techniques to answer specific questions during
naturalistic observation. In a participant-observer study, the researcher joins the group that is studied. While both
types of observational studies raise ethical concerns since they may invade the privacy of others, the participant-
observer study is more problematic. Field studies should not be confused with field experiments, which are true
experiments conducted outside the laboratory.
An archival study is a descriptive method in which a researcher re-examines already existing records for
a new purpose. Data archives may provide demographic information and information about attitudes, which can
help us analyze societal trends or study population subgroups.
Qualitative research relies on words instead of numbers and focuses on self-reports, personal narratives,
and expression of ideas, memories, feelings, and thoughts. Increased interest in qualitative research may
represent a paradigm shift within psychology from reliance on hypothesis testing, experimentation, and
quantitative data analysis. A paradigm is the set of attitudes, values, beliefs, methods, and procedures that are
generally accepted within a discipline. Researchers use qualitative research to study contextual phenomena,
which are phenomena that cannot be understood without the context in which they appear. Many qualitative
studies use methods of empirical phenomenology to gather data. An example is the Contrada et al. (2004) study
of the impact of religiosity on cardiac surgery outcomes. The authors caution that because qualitative research
does not control for potential biases that are carefully controlled in experiments, there may be greater potential for
mistakes and drawing erroneous conclusions.
The authors conclude the chapter with a discussion of the importance of internal and external validity in
both qualitative and quantitative research. Qualitative researchers are concerned with the reproducibility of their
conclusions. The most important measure of the goodness of a qualitative study is whether others can reproduce
its findings.
Handout 3-1: Phenomenology
This exercise was performed in Wilhelm Wundt’s lab in the late 1800s and is a good example of how to
quantify your immediate experience. Set a metronome to beat about once/second (you can embed a repeating
ticking sound file in a PowerPoint slide to produce the same effect). Have students rate the beat on the following
three dimensions: pleasant-unpleasant, strain-relaxation, and excitement-calm.
Perform this task at several different metronome rates. Be sure to return to the original once/second rate
at some point during the exercise. This will allow you to demonstrate the difficulty of replication in phenomenology
work (and also demonstrates the low external validity of some lab research). Comparisons across students will
also allow you to demonstrate the individual differences that are inevitable in this type of research.
Rate 1:
Pleasant Unpleasant
1 2 3 4 5
Strain Relaxation
1 2 3 4 5

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Excitement Calm
1 2 3 4 5
Rate 2:
Pleasant Unpleasant
1 2 3 4 5
Strain Relaxation
1 2 3 4 5
Excitement Calm
1 2 3 4 5
Rate 3:
Pleasant Unpleasant
1 2 3 4 5
Strain Relaxation
1 2 3 4 5
Excitement Calm
1 2 3 4 5

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Case Study
The text points out that case studies which rely upon retrospective data are especially problematic due
to the biases and inaccuracies of memory. This can be quickly and effectively demonstrated in class with the
following exercise. Divide the class into pairs, and have one member of each pair examine a picture you have
brought to class. It is best if the picture has several objects and details to it. Give them a few minutes to study the
picture closely. Later during the class period, or even the next day, have the member of each pair who did not
view the picture ask as many questions as she can of her partner to try to paint the picture in her own mind. Lastly,
compare their different interpretations and reveal the original picture. This exercise exhibits both the difficulty in
coming up with the appropriate questions for a case study and the problems associated with memory errors.
Field Studies
Students need to be able to discriminate field observation from anecdotal evidence. A primary difference,
that field observation relies upon systematic observation, is too often missed. Ask your class if anyone has ever
known someone who had a premonition or ESP-like phenomenon. See if students can explain why these
anecdotes are not good examples of field studies, despite their occurring in the natural environment (Answer:
because scientific investigation involves a predetermined set of guidelines and data-collection techniques). Point
out how essentially all parapsychology discoveries lack this, and are (not coincidentally) unable to predict future
recurrences. Another effective way to explain this is in the context of explaining the steps of the scientific method:
with anecdotal evidence you mistakenly jump right from observation to conclusion, whereas with field observation
you insert the necessary steps of prediction, systematic observation, and data analysis.
Many research questions that you could answer using a survey can also be answered using a field study.
Ask your class to suggest several issues that they might create a survey about (e.g., student drinking habits,
religious beliefs, academic dishonesty). For each issue, have them determine whether a field study might be better
or worse than a survey. Points to cover here include reactivity, time considerations, external validity, participant
honesty, and population sampling.

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1. Describe each of these nonexperimental approaches and give an example of how
each might be used:
(a) Phenomenology is a description of one’s own immediate experience. You
could use this approach to describe your delight when playing with an affectionate
puppy.
(b) A case study is a descriptive record of an individual’s experiences
and/or behaviors kept by an outside observer. This strategy is used to make
inferences about developmental processes, the impact of life events, a person’s
level of functioning, and the causes of disorders. You could use this approach to
document a student’s growth by creating a portfolio that arranges academic work
in chronological order.
(c) A field study involves nonexperimental research performed in a real-life setting.
This category includes naturalistic observation and unobtrusive measures, and
survey tools such as questionnaires and interviews. You could use naturalistic
observation to compare the percentage of student and nonstudent drivers who
“run” red lights or stop signs at a busy campus intersection.
(d) Qualitative research involves nonexperimental methods and relies on words
instead of numbers and focuses on self-reports, personal narratives, and
expression of ideas, memories, feelings, and thoughts. You could use qualitative
research to identify important common themes in narratives by undergraduates
asked to describe their personal growth during 4 years of college.
2. What is meant by external validity? Why are nonexperimental studies often higher
in external validity than true experiments?
External validity is the degree to which research findings can be generalized to
other settings and people. True experiments conducted in a laboratory may be
artificial and unrealistic because of experimental controls over extraneous
variables. Nonexperimental studies are more frequently conducted in real-world
settings with a more diverse sample of participants than true experiments.
3. What is meant by internal validity? Why are nonexperimental studies often lower
in internal validity?
Internal validity is the degree to which a researcher is able to demonstrate a
causal relationship between antecedent conditions and subsequent observed
behavior. Nonexperimental studies are often lower in internal validity than true
experiments because researchers do not create the antecedent conditions or
randomly assign subjects to these conditions. These limitations prevent
researchers from concluding that the antecedent conditions, and not uncontrolled
variables, are responsible for group differences in behavior.
4. What are retrospective data? Why is the use of retrospective data considered a
shortcoming in scientific research?
Retrospective data consist of information collected in the present based on a
subject’s recollection of past events. Four problems threaten the accuracy of
retrospective reports. Subjects often cannot accurately recall all the events

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that occurred on a specific occasion. Their cognitive systems may unconsciously
“reconstruct” memories over time. The subjects’ mood may filter the kind of
events recalled. Finally, current situational cues may bias the information reported.
5. Why are unobtrusive measures preferred?
Unobtrusive measures are procedures designed to assess behavior without a
subject’s knowledge. Researchers prefer them because they avoid the problem of
reactivity by measuring the consequences of behavior, like beach littering in the
Bechtol and Williams (1977) study, after the behavior has already been performed.
6. Devise an unobtrusive measure to establish each of the following:
(a) Which professor at the university is the most popular.
You could compare professors on how often students enroll in more than one of their classes, how quickly their
courses close, and their student drop-out rates.
(b) What are the most popular library books?
Examine book “wear and tear,” the number of book copies that were ordered, library borrowing records, and the
amount of “overdue” fines for the book.
(c) Do people prefer to sit on the left or the right side of the theater when they go to the movies?
Examine “wear and tear” on theater carpet and seats and measure the amount of trash left behind.
(d) How will people vote on the next school millage?
Count the number of yard signs, letters to the editor, or tweets supporting and opposing the millage.
7. For each of the research topics listed here, indicate the type of nonexperimental
approach that would be most useful and explain why.
(a) Pushing ahead in line
Naturalistic observation could gather useful information about “pushing ahead in
line.” We could use naturalistic observation in a supermarket checkout line to
measure both perpetrator and victim characteristics, the frequency, distribution
over time, success of attempts to “push ahead,” and both victim and checkout clerk
responses to these attempts.
(b) Daydreaming
Naturalistic observation, phenomenology, and qualitative research could be
employed to study daydreaming. We could use naturalistic observation in a
campus library or study lounge to measure daydreamer characteristics,
daydreaming frequency, and its distribution over time. A challenging
methodological problem would be how to distinguish daydreaming from napping,
prayer, and meditation. Phenomenology provides access to a daydreamer’s
immediate conscious experience, which cannot be measured using naturalistic
observation. This could reveal how daydreaming feels, how long it seems to last,
and what the daydreams concern. Qualitative studies could examine personal
narratives about daydreaming experiences to describe the participants’ experience
and its meaning for them.
(c) Locating the most popular painting in an art gallery
Naturalistic observation could be employed to identify the most popular
painting in an art gallery. We could use naturalistic observation to count the

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number of subjects examining each painting and how long they viewed each.
We could supplement this information with unobtrusive measures like “wear
and tear” on carpets and floor tiles, which would minimize the risk of reactivity.
(d) Studiousness in college students
Naturalistic observation could assess college student studiousness. We could
measure the number of students and duration of study time in public areas like the
library, dormitory lounges, Student Union, and local establishments like coffee
shops.
(e) Determining whether a particular patient has improved with psychotherapy
The case study method, which collects detailed information about a single subject,
would be the best method to measure a patient’s improvement with psychotherapy.
We could compile extensive data from symptom logs, class attendance records,
grade reports, psychological tests, interviews, and behavioral ratings by
confederates like the patient’s roommate or dating partner. A clinician, with no
relationship with the patient or therapist, should assess progress to avoid the
problem of experimenter bias.
8. For each of your answers to question 7, explain whether an experiment would
generate more useful information than the nonexperimental method you selected.
Would it be possible to set up experiments to explore all these problems? If not,
why not?
Researchers could design experiments to study all five topics. Experiments, which
can achieve high internal validity, could complement the nonexperimental
approaches described in question 7, which are potentially high in external validity.
Experiments could test causal relationships suggested by the nonexperimental
studies.
(a) We could design a field experiment in a supermarket to study “pushing ahead
in line.” We could vary perpetrator characteristics (age, gender, and ethnicity) and
measure their impact on customer acquiescence.
(b) We could design a laboratory experiment to study daydreaming. We could
vary task interest level and task duration, and then measure the effect of these
antecedent conditions on the frequency and duration of daydreaming.
(c) We could design a field experiment to study painting popularity. We could
manipulate antecedent conditions like painting location, lighting, and publicity, and
measure the effect of these changes on subject ratings of painting popularity and
art gallery traffic patterns.
(d) We could design a field experiment to study college student studiousness.
We could vary library hours (extended or regular hours) and measure the
effect of these schedules on student library usage.
(e) We could design a small N study using multiple-baselines to determine whether
a particular patient has improved with psychotherapy. A behavior therapist could
identify two specific problems (stress and headaches) to be treated. The therapist
could initiate a separate intervention designed to treat each problem (stress
management for stress and muscle biofeedback for headaches) after baseline
periods of different length. This study could provide persuasive evidence of
treatment effectiveness if symptoms only improved after the designated
intervention was introduced.

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9. What is the current paradigm in psychological science? What is meant by a
paradigm shift?
A paradigm is the set of attitudes, values, beliefs, methods, and procedures that
are generally accepted within a discipline. The accepted paradigm in psychological
science is reliance on hypothesis testing, experimentation, and quantitative data
analysis. A paradigm shift occurs when scientists replace a previously accepted
paradigm with another, like qualitative research, because it enables better
description, prediction, explanation, and/or control of studied behavior.
10. Design a qualitative study to explore sibling rivalry. Use a method from empirical
phenomenology as your data-gathering technique.
Naturalistic observation and siblings’ oral accounts of their relationship could
provide valuable information about sibling rivalry. We could use naturalistic
observation to measure the frequency, intensity, and duration of competitive
behavior by siblings. The siblings’ oral accounts could provide a rich source of
information regarding their feelings about their rivalry, its meaning to them, and its
role in their development.
Chapter 4
Alternatives to Experimentation: Surveys and Interviews
Chapter Overview
Psychologists use surveys (questionnaires and interviews) in field studies and they can be integrated
into many research designs. Researchers construct surveys to minimize the effects of response styles, such as
willingness to answer, position preference, and yea-saying and nay-saying. Researchers can collect information in
several different ways, including self-administered questionnaires, mail surveys, telephone surveys, and face-to-
face interviews. Self-administered questionnaires may be handed out to subjects or completed using computers
on or off the internet. Mail surveys are a popular and cost-effective strategy. Telephone surveys have become a
popular data collection method, especially using computerized random digit dialing. Face-to-face interviews can
yield high-quality data, but are more expensive due to increased interview time and more extensive interviewer
training. A survey’s goodness can be evaluated by its reliability and validity.
While sampling procedures are important in all psychological research, they are particularly critical for
survey research. The representativeness of our sample of subjects determines our ability to generalize research
findings. While we prefer some form of probability sampling (simple random sampling, systematic random
sampling, stratified random sampling, or cluster sampling), researchers most often obtain nonprobability samples
(convenience samples, quota samples, purposive samples, and snowball samples).
A research report must explain the type of sample used and how subjects were recruited. Researchers
must include details that may have influenced the type of subject who participated in the study and limitations of
who could participate. Finally, researchers should report information about selected subjects whose data were not
included in the report.

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1. Pick a survey topic and list seven objectives for a possible survey.
For a survey concerning internet movie rental services, seven objectives could
include evaluation of these services on cost, selection, title availability, delivery
time, time to credit customers for returns, communication with customers, and
ease of use.
2. Evaluate the pros and cons of open-ended and closed questions.
Open-ended questions like “Why did you become a Psychology major?” require
that subjects respond with a more detailed answer than yes/no, agree/disagree, or
a 1 to 10 rating. Open-ended questions can provide extensive information and
can clarify or expand answers to closed questions. However, answers to open-
ended questions are harder to quantify than answers to closed questions.
Closed questions like “How many Simpson’s episodes did you download last
year?” restrict the number of possible alternatives. While responses to closed
questions are easier to quantify than answers to open-ended questions, they often
generate less complete information.
3. How are open-ended questions quantified? Give an example of an open-ended
question and how you might quantify the responses. How else might you do it?
Researchers quantify open-ended questions using content analysis, which is
analogous to coding behaviors using systematic observational techniques. A
sample open-ended question is “What is important to you when you choose a
Spring Break vacation?” A researcher might quantify student responses by
assigning responses to categories (cost, distance, popularity, weather, legal
drinking age, accommodations, shopping, and other) and report the frequencies for
each category or perform a statistical analysis on these responses.
4. Imagine that you are writing survey questions for the topic you chose for item 1
above. Select one objective and design four questions to explore it: one using a
nominal scale, one using an ordinal scale, one using an interval scale, and one
using a ratio scale.
For a survey objective of rating internet movie rental service selection, questions
could include:
Nominal scale: “Which movies have you rented from Netflix?”
Ordinal scale: “Rate your satisfaction with Netflix’s movie selection using one of the
following choices: Unacceptable Poor Neutral Good Excellent.”
Interval scale: “Rate your satisfaction with Netflix’s movie selection from 1-10
where 1 means complete dissatisfaction and 10 means complete satisfaction.”
Ratio scale: “Rate your satisfaction with Netflix’s movie selection from 0-100 where
0 means complete dissatisfaction and 100 means complete satisfaction.”
5. When designing survey questions, how would you control for each of the
following response styles?
a. Willingness to answer
Willingness to answer is a special concern when questions require detailed

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knowledge. When subjects are unsure of their answers to these questions,
some will skip the questions and others will guess. Researchers may
encourage subjects to guess the answer when they are unsure or say nothing
to subjects about this issue, since there is no definitive strategy for controlling
this response style.
b. Position preference
Position preference is the tendency to select a response located in a certain
position when unsure about an answer. Test builders vary the position of correct
answers throughout a test (answer b is not always the correct answer). Likewise,
pollsters also vary the position of “pro” and “con” responses throughout a survey
(answer b is not always “pro-choice”).
c. Yea- or nay-saying
Yea-saying and nay-saying are agreeing or disagreeing with a question regardless
of its manifest content. Since subjects ignore the plain meaning of the question,
this threatens a questionnaire’s external validity. Researchers use several
strategies to control this response style. They build specific content into response
options to force subjects to think harder about their answers.
Even when yes/no items are used, as in the Unfounded Optimism Inventory,
researchers vary their direction so that a high score requires both yes and no
answers.
6. What is wrong with this question? “Do you think it is acceptable to kill animals with
painful procedures and use them to advance scientific knowledge to benefit human
beings?” Rewrite the item.
The question is emotionally-loaded with words like kill and painful, and double-
barreled because it contains ideas about killing and inflicting pain, and using
animal research to benefit human beings.
This question should be broken into separate neutrally-worded questions. For
example:
Animals are often used in research designed to advance scientific knowledge to
benefit human beings. Rate how acceptable the following animal research
practices are to you from 1 (highly unacceptable) to 5 (highly acceptable).
a. administering mild electric shocks
b. administering painful electric shocks
c. ending their lives
7. What type of measurement scale is being used in each of these instances.
a. A researcher measures the brand of car purchased by subjects who heard
one of three advertising campaigns.
Car brands can be classified using a nominal scale since cars can be
assigned to separate categories.
b. A counselor compares the frequency of divorces in couples who had marriage
counseling and those who did not.
Divorce rate can be measured using a ratio scale since there is a true
zero point and equal intervals between values.
c. A seamstress estimates how much fabric will be needed to make a coat.

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Quantify of fabric can be measured using a ratio scale since surface area is a
physical variable with a true zero point and equal intervals between values.
d. Three racks of sweaters are labeled “small,” “medium,” and “large.”
Sweater size implies an ordinal scale since the racks are arranged in increasing
size.
e. On a scale from 0 to10 (0 = not at all; 10 = extremely), how hungry are you
right now.
The hunger scale would be interval scale if there is no true zero point, but
the intervals are equal. It would be ordinal scale if the intervals are not equal
and larger numbers correspond to increasing hunger.
8. You have designed a survey for nurses, and you have mailed it to 500 nurses
across the country. It has now been several weeks since you mailed out the
surveys, but so far only 20% of the nurses have filled out and returned the survey.
What are three things you could do to increase the response rate?
Researchers can increase response rates by keeping the questionnaire short,
including a convincing cover letter and stamped self-addressed envelope,
protecting participant anonymity, and providing a small gift or prize drawing. When
the response to your first mailing is low, a second mailing to people who did not
return the survey can add 50% to the number of returned surveys.
9. What are the pros and cons of telephone surveys and face-to-face interviews?
Telephone surveys can achieve response rates between 60% and 90% when
repeatedly calling a randomly-dialed telephone number. Well-trained interviewers
can obtain high-quality answers, particularly with nonthreatening questions.
However, concern about social desirability might reduce forthright answers about
extremely sensitive topics. Telephone surveys are usually limited to closed
questions.
Face-to-face interviews are one of the best ways to obtain high-quality data, but
this is the most expensive method for collecting survey data in terms of time and
cost. Interviewers require thorough training in interviewing skills and techniques. A
face-to-face interview typically takes more than twice as long to conduct than its
phone counterpart. Finally, the interviewers’ physical appearance and nonverbal
behavior may influence subject responses, which is not a problem in telephone
surveys.

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10. What is the difference between reliability and validity?
Reliability is the extent to which a survey is consistent and repeatable. If a survey
is reliable, responses to similar survey questions should be consistent, the survey
should generate very similar responses across different survey-givers, and the
survey should generate very similar responses if it is given to the same person
more than once.
Validity is the extent to which a survey actually measures an intended topic. There
are several aspects of validity: Does the survey measure what you want it to
measure? Does performance on the survey predict actual behavior? Does it give
the same results as other surveys designed to measure similar topics.
11. Explain the difference between probability sampling and nonprobability
sampling and describe the different forms of each.
Probability sampling involves choosing subjects using a procedure that allows us
to calculate their chance of selection from a population. Researchers use four
forms of probability sampling: simple random sampling, systematic random
sampling, stratified random sampling, and cluster sampling.
Simple random sampling is the most basic form of probability sampling.
Researchers select subjects using an unbiased procedure (like a table of random
numbers) in which each subject has an equal chance of being included in our
sample. Random sampling only provides an estimate of what is likely to be true. An
unbiased selection procedure does not ensure a representative sample because it
does not control sample demographics.
In systematic random sampling, where all members of a population are known, a
researcher can randomly select every nth person from the population, where n is
determined by the size of the population and desired sample size.
In stratified random sampling, researchers identify and randomly sample from each
important population subgroup (like “Democrats” and “Republicans”) in the same
proportion as found in the population. This method increases the precision of our
estimates and is used extensively by professional polling operations.
In cluster sampling, researchers randomly sample from groups (like zip codes and
counties) that already exist. This allows us to sample efficiently from a limited
number of locations.
Nonprobability sampling chooses subjects using a biased procedure. Quota
sampling, convenience sampling, purposive sampling, and snowball sampling are
four forms of nonprobability sampling. In each case, researchers do not select
subjects at random. Since they do not know a person’s odds of being selected,
they do not know whom the sample represents.
In quota sampling, researchers recruit subjects until they meet a predetermined
quota that mirrors the makeup of the population.

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In convenience sampling, researchers recruit subjects who are convenient to study
(such as students who showed up for class). This is a weak form of sampling since
researchers do not control a sample’s representativeness.
In purposive sampling, researchers select nonrandom samples based on the
specific purpose of the study (studying the success of a new employee training
program in a company’s sales and human resources departments). Since
researchers do not control a sample’s representativeness, they must be very
careful in generalizing their findings to other members of the population.
In snowball sampling, researchers locate individuals who meet the sample criteria
(animal rights activists) and ask them to find or lead them to additional individuals.
This method is mainly used when sampling very small, uncommon, or unique
populations when researchers do not know who the population members are or
how to contact them. Again, since researchers do not control a sample’s
representativeness, they must be very careful in generalizing their findings to other
members of the population.
12. Discuss the logic behind random selection and why it is important in research.
In random selection, each member of the population we are studying has an
equal chance of being included in our sample. Random selection is critical to
research because it increases the chance of obtaining a sample that represents
the population. Representative samples contribute to the external validity of our
studies by allowing us to generalize to people we have not studied. This increases
the usefulness of our findings.
13. Evaluate each of the following as a technique for obtaining a random sample of
subjects.
Since we have not defined the population of interest, we cannot determine
whether these procedures will select a random sample from that unknown
population. Each of these procedures introduces considerable sampling
bias, especially the requirement that our sample be composed of volunteers.
Volunteers tend to be more sociable, report more liberal attitudes, and score
lower on authoritarianism than nonvolunteers.
(a) An experimenter obtains subjects by asking every third driver stopping at the
stoplight on the corner of Hollywood and Vine streets in Los Angeles to be in an
experiment.
This method could limit the sample to people in Los Angeles, who take this
route, use cars (instead of buses and bicycles), drive the cars (this excludes
passengers), stop at intersections long enough to be approached, and are
willing to volunteer for a psychology experiment.
(b) A researcher places an ad in a local paper asking for volunteers for a
psychology experiment.
This method could limit the sample to people who read the local paper or have
it read to them, and are willing to volunteer for a psychology experiment.
(c) An experimenter calls every fourth number in the phone book and asks for
volunteers for a research project.
This method could limit the sample to people with phones and listed numbers,
who do not screen their calls, and are willing to volunteer for a psychology
experiment.

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(d) A wealthy graduate student posts signs on the university bulletin boards
offering $8 per hour for participating in a 2-hour perception experiment.
This method could limit the sample to people who are sighted, able to read the
language used on the posters, on campus, who pass by the researcher’s bulletin
boards, and are willing to volunteer for $8 per hour (which may result in a
disproportionate number of subjects in financial need). Finally, the perceptive
reader will realize that the phrase, “wealthy graduate student,” is an oxymoron.
14. Using Table B1, the random number table in Appendix B of this book, select a
random sample of 10 subjects from a subject pool of 20.
Assign a different number from 1 to 20 to each of the 20 people in the subject pool.
Randomly choose a starting place in the random number table and move
systematically through the table. Select the first 10 numbers between 1 and 20 to
complete the sample.
Chapter 5
Alternatives to Experimentation:
Correlational and Quasi-Experimental Designs
Chapter Overview
Nonexperimental approaches to research like correlational and quasi-experimental designs can
complement experiments. While it is much more difficult to conclusively establish cause and effect relationships
using these techniques, they can achieve high external validity.
Correlational studies may be performed in the laboratory or in the field. A correlation is the degree of
relationship between two traits, behaviors, or events. We cannot infer cause and effect from a correlation due to
the problems of causal direction, bidirectional causation, and the third variable problem. When two variables are
strongly correlated, we can predict the value of one if we know the value of the other using linear regression
analysis. Researchers can study the interrelationships among three or more variables using multiple correlation
and predict the value of one variable if we know the values of the other related variables using multiple regression
analysis.
Researchers can use sophisticated correlational methods to create causal models using a cross-lagged
panel design or path analysis. While causal models can suggest cause and effect relationships, they cannot
conclusively establish causality because we cannot completely rule out other potential influences and the problem
of causal direction.
Quasi-experimental designs “seem like” experiments, but are not. They are valuable when researchers
cannot randomly assign subjects to different treatments. Researchers can use quasi-experiments to explore the
effects of different treatments on preexisting groups of subjects or to study the same naturally occurring events,
characteristics, and behaviors that they measure in correlational studies. An ex post facto study explores the
effects of subject characteristics (subject variables) without manipulating them. A nonequivalent groups design
examines the effects of a treatment on preexisting groups of subjects.
Quasi-experimental designs examine changes in the same group of subjects over time or differences
among cohorts at one point in time. Longitudinal studies measure the same group of subjects at several points in
time. Cross-sectional studies select groups of subjects who are already at different stages and compare them at a
single point in time. Researchers use a pretest/posttest design to assess whether an event alters behavior, but
this design is low in internal validity due to problems like pretest sensitivity and confounding by outside influences.
While correlational and quasi-experimental designs achieve low internal validity, they can show
relationships, predict behavior, and generate research hypotheses that can be tested in future research.

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Handout 5-1: Identifying Research Designs
Pretend each of the following statements is a conclusion based on a scientific study (but trust me, these are fake!).
For each one, state which research design(s) could have been used in the study (check all that apply). Choose the
method that you think would have been best, and describe what the study must have been like using that method.
“People raised in the Midwest are happier than people raised near either coast.”
___ Correlational study ___ Longitudinal study ___ Pretest/posttest study
___ Ex post facto study ___ Cross-sectional study
Describe a possible study here:
“The more time you spend social networking as a child, the better you perform in college.”
“Students perform better on the GRE after they have studied Experimental Psychology.”
“The older you are, the better you get at communicating with other people.”

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“Students who join fraternities/sororities have larger wardrobes than those who don’t.”

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1. What is a correlation? When can it be used?
A correlation is a statistic that indexes the strength of a relationship between two
traits, behaviors, or events. We cannot infer causal relationships from correlations
since there is no way to establish causal direction or to rule out bidirectional
causality or the possible role of third variables. Consequently, correlational studies
achieve low internal validity.
To calculate a Pearson Product Moment Correlation Coefficient, you need data
from two continuous variables. These data can be obtained through experimental
or nonexperimental studies. Correlational studies allow us to examine relationships
that would be impossible or unethical to explore using experiments, like the role of
childhood sexual abuse in teenage pregnancy.
2. Leilani just computed the Pearson Product Moment Correlation Coefficient for two
sets of data. She got r = 2.30. Leilani is thrilled, marveling at what a large
relationship she found. What can she conclude from her findings?
Leilani should conclude that she miscalculated the Pearson r, since this statistic
only ranges from –1 to +1.
3. A college administrator has located a new aptitude test that is correlated with
academic achievement (r = -.54). The admissions committee of the college now
uses a screening test also correlated with academic achievement, but the
correlation is r = +.45. Which test would be a better choice if the admissions
committee is interested in predicting how well prospective students will do at the
school? Explain your answer.
The administrator should select the new aptitude test since it better predicts
academic achievement. The larger the absolute value of a correlation, the greater
its predictive power. We can demonstrate this using the coefficient of
determination since it estimates the amount of variability in scores on one variable
that can be explained by a second variable. The coefficient of determination is
larger for the new test (.29) than the current test (.20). Your students should
realize that this is a contrived example since aptitude scores on valid tests are
positively correlated with academic achievement.
4. A researcher found that variable X and variable Y are very strongly correlated. She
claimed that variable X causes variable Y to occur. Why can’t this statement be
made?
This claim misuses statistics because correlation cannot prove causation.
Correlation studies achieve low internal validity because they do not randomly
assign subjects to treatment conditions. Further, the problems of causal direction,
bidirectional causation, and third variables prevent researchers from drawing
causal conclusions from correlations.
Causal direction means that since a correlation is symmetrical, we have no basis
for concluding that X caused Y. Y could have just as easily caused X.
Bidirectional causation means that both variables affect each other. The third
variable problem means that a hidden variable is responsible for values of both X
and Y, and the appearance of a causal relationship between them.
5. How are beta weights used to construct paths in a path analysis?

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We obtain beta weights from multiple regression analysis in which scores from two
or more variables are used to predict the value of another variable. A beta weight
indexes each variable’s relative predictive power. We can use beta weights in path
analysis to construct path models that represent possible causal sequences for
these intercorrelated measures. For example, the study by Serbin and colleagues (1990)
confirmed that different models better predicted boys’ and girls’
academic performance.
6. What does a cross-lagged panel design attempt to do? What cannot be
ruled out as an alternative to any cause and effect model found with a cross-
lagged panel design?
A cross-lagged panel design measures subjects at two points in time on the same
pair of related behaviors or characteristics. Researchers calculate correlations on
these scores and then examine the diagonal correlations (between two different
variables) to infer a causal path. Models constructed using this design are
inconclusive because bidirectional causation and the third variable problem cannot
be ruled out as alternative explanations.
7. Define the term quasi-experiment and discuss the pros and cons of quasi-
experimentation.
A quasi-experiment is a nonexperimental design that resembles an experiment, but
is not, because it does not randomly assign subjects to treatment conditions.
These designs include ex post facto studies, longitudinal designs, cross-sectional
studies, and pretest/posttest designs.
Pros: quasi-experiments allow us to study the effects of different treatments on
preexisting groups of subjects (e.g., the comparative effectiveness of
antidepressant medication for men and women) and the influence of naturally
occurring events, characteristics, or behaviors on variables of interest (e.g., the
impact of an influenza epidemic on the prevalence of schizophrenia).
Quasi-experiments may be the only means of studying a relationship when
subjects cannot or should not be randomly assigned to treatment conditions. They
can achieve greater realism than is often found in experiments. Finally, they are a
valuable source of experimental hypotheses.
Cons: we can never establish cause and effect relationships using quasi-
experiments because they do not randomly assign subjects to conditions.
8. Explain the pros and cons of longitudinal versus cross-sectional studies.
Longitudinal studies require fewer subjects and may achieve greater statistical
power than cross-sectional studies. They also avoid confounding by preexisting
differences among groups of subjects since the same subjects are studied over
time. However, longitudinal studies are more time consuming, harder to conduct,
and risk greater subject attrition than cross-sectional studies.
9. Claire conducted an ex post facto study comparing attitudes of a group of rap
music fans and a group of classical music buffs. She found that the rap fans had
more sexist attitudes about women than the other group did. She claimed that rap
music causes people to become sexist. Explain why she cannot say that from the
results of her study? How can her results be stated accurately?
Ex post facto studies are low in internal validity because they do not randomly
assign subjects to different treatments. Claire’s conclusion is not supported by her
design since she compared the attitudes of preexisting groups instead of
randomly exposing subjects to either rap or classical music. Since her rap music
fans and classical music buffs already had different music preferences, they may
have also differed on other subject variables. These variables could include family

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structure, level of education, parenting style, religious denomination, and
socioeconomic status. One or more of these differences might be responsible for
sexist attitudes.
Claire can accurately state that the rap music fans in her sample reported more
sexist attitudes about women than did the classical music buffs.
10. What four groups are needed in the Solomon 4-group design?
A Solomon 4-group design is an extension of a pretest/posttest design and
includes the following groups:
1. group that received both the pretest and posttest, but not the treatment
2. group that received the treatment and only the posttest
3. group that received only the posttest
4. group that received the pretest, treatment, and posttest

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11. Design a correlation-based study or a quasi-experiment to test each of the
following:
a. Hot weather is associated with higher rates of violence in the streets.
Select 25 major metropolitan cities, obtain average temperature readings and
number of violent crimes committed for the same month period, and calculate a
Pearson Product Moment Correlation Coefficient. A significant positive correlation
would support the hypothesis.
b. Rap music causes people to become more sexist (rather than the other way
around).
A cross-lagged panel design can suggest a potential causal relationship between
exposure to rap music and sexist attitudes, but cannot prove that one exists.
Measure time spent listening to rap music and degree of sexism in the same group
of subjects at ages 12 and 15. If the strongest correlation is between time spent
listening to rap music at age 12 and degree of sexism at age 15, this would support
the hypothesis.
c. Childhood schizophrenia can be predicted from cognitive deficits, genetic
predisposition, and autonomic arousal in childhood.
Measure cognitive deficits, genetic predisposition, and autonomic arousal
(predictor variables), and severity of schizophrenic symptoms in a sample of
subjects diagnosed with childhood schizophrenia. Use multiple regression
analysis to determine whether the predictor variables account for a significant
percentage of the variability in schizophrenic symptoms.
d. Older people exercise less than middle-aged people.
Use a cross-sectional study to test this hypothesis. Operationally define older
and middle-aged people, and exercise. Select a sample of both age groups, ask them to
complete a daily exercise diary for one month, and then compare their
data.
e. A college education increases people’s SAT scores.
Use a pretest/posttest design to test this hypothesis. Select a sample of students
who completed the SAT for college admission and readminister the SAT during
their final semester before college graduation.

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12. For each study you designed for question 11, list all the reasons you can think of
that explain why your study would be low in internal validity.
All of these studies are low in internal validity because the subjects were not
randomly assigned to treatments. Each study has specific problems that prevent
us from making causal inferences.
a. Hot weather is associated with higher rates of violence in the streets.
If hot weather is correlated with higher rates of violence, this does not mean that
the relationship is causal. For example, hot weather might coincide with periods
when high risk groups are out of school or unemployed, which might independently
increase the opportunity and motivation for violence.
b. Rap music causes people to become more sexist (rather than the other way
around).
A cross-lagged panel design cannot rule out bidirectional causation or the third
variable problem. Preference for rap music and sexism might influence each
other, or a third variable like family structure or parenting style might influence both
music preference and sexism.
c. Childhood schizophrenia can be predicted from cognitive deficits, genetic
predisposition, and autonomic arousal in childhood.
Multiple regression analysis cannot rule out third variables like exposure to a virus
like influenza, rejection by the mother’s immune system, or malnutrition, which
could influence cognitive deficits, autonomic arousal, and severity of schizophrenic
symptoms. None of these third variables could discount a predictive relationship
between genetic predisposition and the severity of childhood schizophrenia.
d. Older people exercise less than middle-aged people.
A cross-sectional study cannot explain differences in exercise between these age
groups. Differences in amount of exercise might be due to differences in
opportunities and social support for exercise, and not age itself.
e. A college education increases people’s SAT scores.
A pretest/posttest design has very low internal validity because practice effects and
extraneous variables like test-taking motivation could account for higher scores.
Chapter 6
Formulating the Hypothesis
Chapter Overview
Experimental research depends on developing hypotheses. A nonexperimental hypothesis is not a
statement about cause and effect. Instead, it predicts the relationship a researcher expects to find between two or
more variables. An experimental hypothesis provides a tentative causal explanation of an event or behavior. It
must be a synthetic statement that is falsifiable and testable. It should also be parsimonious, which means that it
requires the fewest supporting assumptions. The most fruitful or heuristic hypotheses stimulate further research.
Experimental hypotheses cannot be analytic or contradictory statements because these statements cannot be
falsified. Since analytic statements are always true and contradictory statements are always false, we do not need
to conduct experiments to test them.

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Researchers develop experimental hypotheses using induction, deduction, prior research, serendipity,
intuition, and observation. The processes of induction and deduction are central to hypothesis development.
Researchers use both processes to generate testable hypotheses. Induction helps us devise general principles
and theories that organize, explain, and predict behavior. Deduction allows us to test the implications of these
principles and theories.
A review of prior research can help narrow down possible explanations and generate experimental
hypotheses. Nonexperimental studies can suggest causal explanations that can be tested by experimental
hypotheses. Serendipity, the knack of finding something you did not seek, can be a valuable source of hypotheses
when we are open-minded and can appreciate the significance of an unexpected observation. Intuition is most
likely to generate valuable hypotheses when it comes from experts. Finally, everyday observation of behaviors
and real-world problems can suggest hypotheses when all else fails.
The first step in designing research and writing a research report is to conduct a thorough literature
search. Psychologists mainly locate the Abstracts of psychological journal articles relevant to their research topic
using PsycINFO computer searches. Meta-analyses conducted on your topic are a highly useful type of research
article. The articles you select provide the basis for the Introduction section of the report and can also be used in
the Discussion section to provide a context for your experimental findings.
Classroom/Homework Exercises
Handout 6-1: Experimental and Nonexperimental Hypotheses
Listed below are several possible hypotheses. For each one, indicate whether it is experimental or
nonexperimental in nature. Also, suggest a research method that could test the statement (e.g., correlational study,
longitudinal study, or experiment).
The wealth of a man is directly related to his popularity.
___ Experimental ___ Nonexperimental
Research method:
People with Type A personalities have better math skills than people with Type B personalities.
Research method:
Memory for a list of words is better when the list is heard compared to when it is read.
Research method:

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Handout 6-2: Hypothesis Generation
Suppose you are interested in identifying the factors that cause a student to go to the library. Generate a list of 10
possible reasons why a person might go to the library. Feel free to be creative, but stay within the realm of
possibility (e.g., maybe they go because it has the cleanest bathroom on campus). Once you have a complete list,
rank order the items in terms of how likely each one is to be a true cause. Lastly, describe how you could conduct
studies to test the actual roles of your top three rankings.
Rank: Factor:
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
___ __________________________________________________________
Describe possible research ideas here:

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Handout 6-3: Induction and Deduction
For each of the following scenarios, indicate whether inductive or deductive reasoning was used in reaching the
conclusion that is stated.
Professor Tolman has found that all students who earn an A in Senior Seminar do well on the senior exit exam.
Since John earned an A in Senior Seminar, Professor Tolman predicts that he will do well on the senior exit exam.
___ Inductive ___ Deductive
Shirley is walking through campus when she oversees a chemistry major throwing a cigarette butt onto the
sidewalk. She concludes that all chemistry majors are litterbugs.
Fred observes several students running out of the cafeteria holding their stomachs. He determines that today’s
dinner is not very good.
Amy knows that only psychology majors can enroll in the Research Psychology course. When she sees that Sarah
is enrolled in the class, she concludes that Sarah is a psychology major.
1. What is a hypothesis? What is the difference between a nonexperimental
hypothesis and an experimental hypothesis?
A hypothesis is the thesis, or main idea, of an experiment. It is a statement about a
predicted relationship between two or more variables.
A nonexperimental hypothesis predicts relationships among events, traits, and
behaviors, and is not a statement about cause and effect.
An experimental hypothesis is a synthetic statement that provides a tentative
causal explanation of an event or behavior. Experimental hypotheses must be
falsifiable and testable, and should be parsimonious and fruitful.
2. What are the characteristics of a good hypothesis?
A good hypothesis is synthetic, testable, falsifiable, parsimonious, and fruitful.
3. Which of the following are synthetic statements? Why?
a. If I am cold, then it is December.

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b. Out of sight, out of mind.
c. Virtue is its own reward.
d. A statement that is always true is never true.
Statements a, b, and c are synthetic statements since they can be either true or
false. Statement d is an contradictory statement since it is always false.
4. Explain the differences between induction and deduction. Describe the way they
are used together to create theories and generate hypotheses.
Induction is the process of reasoning from specific cases to more general
principles. Deduction is the process of reasoning from general principles to make
predictions about specific instances.
Induction and deduction are complementary processes that are often combined.
Researchers use induction to devise principles or theories to organize, explain,
and predict behavior. They use deduction to construct hypotheses they can
rigorously test.
5. Is a discovery made through serendipity just a matter of luck? Explain your answer.
Serendipity is the knack for finding things that are not being sought. For example,
Pavlov discovered a phenomenon (classical conditioning) unrelated to the problem
he was studying (digestive glands).
Chance is insufficient to produce a discovery. Pavlov discovered classical
conditioning because he recognized the importance of his unexpected finding, was
open-minded about its theoretical implications, and tenaciously exploited this
opportunity.
6. a. What is the role of intuition in research?
Intuition, which is knowing without reasoning, is a source of experimental
hypotheses.
b. Is intuition scientific?
As a cognitive process, intuition is, itself, neither scientific nor unscientific. How
we study these hunches determines whether our research is scientific. We should
examine our hunches in the context of prior studies to avoid pointless research.
To qualify as scientific research, we must translate our hunches into synthetic
“if…then” statements and then test these hypotheses using the scientific method.
c. Why are our hunches often correct?
When our hunches are correct, this is because they are not random, but based on
experience with relevant research literature and behavior. Simon (1967) argued
that good hunches depend on our expertise.
7. Before you set up an experiment, you should conduct a review of the research
literature. What is the purpose of such a review?
A literature review identifies important issues, alerts us to problems that warrant
further study, helps generate new hypotheses, and prevents us from
unintentionally replicating prior experiments.

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8. Dr. G. has just completed a study that shows a correlation between the amount of
time children watch television and their attention spans. Assume the correlation
was r = -.34. State an experimental hypothesis based on this finding and devise a
simple procedure for testing it.
A possible experimental hypothesis is, “If children watch television, then their
attention span will decrease.”
We can randomly assign children to one of two conditions. Children in the
experimental condition watch television for 2 hours, while those in the control
condition engage in free play (without television) for 2 hours. At the end of 2
hours, we measure how long each child examines a new, unfamiliar toy. We then
compare both groups’ attention span scores to see whether the data falsify or
support our experimental hypothesis.
9. Mary is lost: She just cannot think of a hypothesis. Give her some advice about
how to proceed.
Encourage Mary to start with one or two broad areas of psychology (e.g., learning
and memory) that interest her and to reread the corresponding sections of an
introductory psychology text. Now, she may be able to narrow down her list of
topics to a single topic (e.g., learning lists of words). Next, she should read the
latest studies on her topic. She can use induction to find general principles and
deduction to make specific predictions. She can read the Discussion section of her
journal articles, where authors often identify unanswered questions and suggest
ways to refine their studies. Finally, she can convert nonexperimental studies into
experiments.
Mary can turn to the real world for ideas. She can observe public behavior to form
hypotheses about the antecedent conditions that affect people’s actions. She
can also select a real world problem (e.g., the elderly’s difficulty reading road
signs) and try to determine its causes.
10. Select one of the research areas listed below. Review some of the prior work in
that area and formulate a new experimental hypothesis based on your review.
a. Paired-associate learning
b. The influence of a mental set in problem solving
c. Solving anagrams (scrambled words)
d. Bystander apathy
e. The mere exposure effect
Suggest that your students reread the appropriate section of an introductory
psychology text for a summary of previous findings. Then, they can propose a
synthetic statement in an “if…then” format that predicts the effects of specified
antecedent conditions on a measured behavior.
11. Sit in a public place and observe people for an hour. Write down all the hypotheses
that come to mind to explain their behaviors.
Student answers will depend on their understanding and ability to apply this
chapter, their observational skills, and the setting and time they choose for
observation.
Chapter 7
The Basics of Experimentation
Chapter Overview

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Independent and dependent variables are central to experimental research. The independent variable is the
antecedent condition an experimenter deliberately manipulates to assess its effect on behavior. There are three
types of independent variables (environmental, task, and subject). The dependent variable indicates change in
behavior. Researchers create operational definitions for independent (experimental operational definition) and
dependent (measured operational definition) variables. Operational definitions provide precise meanings for both
unseen processes (hypothetical constructs) and observable behavior (nonconstruct variables) in an experiment,
and allow replication by others.
In designing an experiment, researchers can choose among four levels of measurement: nominal, ordinal, interval,
and ratio. These scales provide increasing information about a variable. Nominal scales completely ignore
magnitude and assign items to distinct categories on the basis of a common feature. Ordinal scales rank items on
the basis of magnitude. Interval scales measure magnitude along scales with equal intervals between all values.
Ratio scales measure magnitude along scales that have both equal intervals between values and a true zero point.
When several levels of measurement “fit” equally well, the authors recommend selection of the highest level
because it provides the most complete information about a variable.
Researchers evaluate operational definitions in terms of reliability and validity. Reliable procedures produce
consistent and dependable outcomes. Three methods of checking the reliability of measurement techniques
include interrater reliability, test-retest reliability, and interitem reliability. Valid operational definitions manipulate
and measure the variables we intend to study. Five criteria for evaluating validity include face validity, content
validity, predictive validity, concurrent validity, and construct validity.
An experiment is internally valid if we can be sure that the changes in behavior that occurred across treatment
conditions were caused by the independent variable. Sometimes we discover that extraneous variables, variables
that are neither independent nor dependent variables, also change across conditions. When both extraneous and
independent variables change value from one condition to another, we have a situation known as confounding.
Confounding threatens internal validity because it prevents us from inferring a causal relationship between the
independent and dependent variables. Campbell and colleagues have identified eight classic threats to internal
validity. These threats include history, maturation, testing, instrumentation, statistical regression, selection, subject
mortality, and the set of selection interactions.
Handout 7-1: Conceptual and Operational Definitions
For each of the terms listed below provide a conceptual definition (a commonly accepted description of the term),
an experimental operational definition (as if the term represented an IV manipulated in an experiment), and a
measured operational definition (as if the term represented a DV measured in your experiment).
Intoxicated
Conceptual:
Experimental Operational:
Measured Operational:
Religious
Conceptual:

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Introverted
Conceptual:
Optimistic
Conceptual:
Immature
Conceptual:

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Levels of Measurement
This chapter describes four levels of measurement a variable might have (nominal, ordinal, interval, ratio). With a
little creativity, many variables can be found to work with two, three, or even all four levels. For each of the
following terms, ask the class to indicate all levels that are possible for the variable (each has more than one).
Have them explain their answers. Alternatively, you can also break your class into small groups for this exercise
and have the groups compete to identify the most levels.
Intelligence
The “hotness” of chili in a bake-off contest
Memory
Tendency to procrastinate
Membership in student organizations
Creating a Survey
Assign students the difficult task of creating a good survey. Ask them to create a 10-question survey to measure a
person’s introversion. Instruct them to use their knowledge about Likert-type scales, interitem reliability, content
validity, and response set (all terms from this chapter) to create the instrument. Once students have each created
one, they can answer several of their classmates’ surveys and then assess their concurrent validity.

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