Evaluation apprehension, social desirability effects
Researcher makes use of naturally occurring differences in the IV. Also called quasi experiment.
The main research methods used by psychologists are :
-Self report method
The method used by researchers to
study cause-and-effect relationships.
Manipulates an independent variable (IV) in order to
investigate the change in dependent variable.
All other variables which might influence the results
(called extraneous variables) are controlled.
Participants are randomly allocated to the
experimental and control conditions.
Independent variable (IV):
the variable that is
Dependent variable (DV):
the variable that is
Experimental group: exposed to
the manipulation of the IV
Control group. Responses of the
control group are compared with
the responses of the
The experiment is carried out in a controlled
• Variables are easier to
• High internal validity
• Procedures can be easily
• High levels of control may
lead to artificiality of the
• Ecological validity of the
study may be a concern
•Increased risk of demand
Experimental investigations carried out in natural
settings (e.g. homes, school).
Involve direct control of the IV and allocation of
participants to groups.
• Improved ecological
validity. Behaviour studied
is more realistic.
• Decreased risk of demand
• More difficult to control
• Internal validity of the
study may be affected.
• More difficult to
The researcher neither directly controls the IV nor
allocates participants to conditions.
Makes use of naturally occurring differences in the IV
in the pre-existing groups.
• Reduced demand
• Degree of control over the
IV is less.
• Difficult to make causal
Variables are not deliberately manipulated by the
Allows psychologists to study behaviour in more
However reduced level of control over the
variables make it harder to draw any conclusion
concerning cause-effect relationships.
Self-report techniques including
questionnaires and interviews
A basic research method; behaviour is observed and
No deliberate manipulation of variables
Observational research can be laboratory or
Observes behaviour through behaviour categories
Open to subjective bias.
Researcher must define the behaviour he/she observes.
Psychologists use behavioural categories to record particular
instances of behaviour.
For example, observers may use check lists or tally chart for
Sampling techniques used for observation can be time sampling
and event sampling.
Crying , fussing
STATE OF A BABY DURING A
30-SECOND TIME PERIOD
Concerned with the extent of relationships between
variables that covary (varies in the same time period)
Correlational analysis do not establish causal links.
Other variables may influence any measured
As a result, the internal/external validity of the study
can be affected.
In this technique, the participants themselves provide
information about specific things relating to themselves.
(e.g. What they think, believe or do)
Questionnaires and interviews- Open or close
Interviews can be:
Structured interviews can be easily repeated.
Unstructured interviews- questions that evolve are
dependent on answers given.
Main disadvantage of self-report measures:
Social desirability bias.
When designing a questionnaire, there are some important
things to be considered.
1. Type of data. Open ended questions will give qualitative
data and close ended questions will give quantitative data.
Items and responses should be simple and clearly defined.
3. Double-barrelled questions.
Avoid two parts in a single question.
4. Leading questions
Avoid questions that lead the participant towards a particular
A detailed study of a particular individual,
institution or event.
Uses information from a range of sources.
Techniques involved to collect data include
interview, psychological tests, observations etc.
Are generally longitudinal.
Difficult to generalise from specific cases.
Aims and hypotheses
An aim is a statement of the purpose of a study.
Hypothesis is a statement that is testable. A research hypothesis is a general prediction
made at the beginning of an investigation , about what the researcher expects to happen.
Types of hypotheses
Experimental hypothesis/alternative hypothesis predicts that something other
than chance alone has played a part in producing the results obtained.
Null hypothesis predicts that the results obtained from an investigation are due to
Alternate hypothesis can be directional or non-directional.
(the direction of a difference or relationship is or is not stated).
A directional hypothesis predicts the direction in which results are
expected to occur.
A non-directional hypothesis does not predict the expected direction of
E.g. of a directional hypothesis. More words are recalled from a list
when using rehearsal as mnemonic technique than when no mnemonic
technique is used.
E.g. of a non-directional hypothesis. There is a difference in the number
of words recalled from word lists presented with or without the presence
of background music.
There are different
participants in each
group of the experiment
Each participant is
involved in only one
condition of the
•Each participant is involved
in all conditions.
i.e. The same participants are
used in both the experimental
and control conditions.
There are different
participants in each
condition. But there are
matched on relevant
variables (e.g., age,
Repeated group design
All the variables other than the independent variable that might
affect the dependent variable are called extraneous variables.
If a variable other than the IV, produces a change in a DV, the
results of the study are said to have been confounded.
CONTROL OF VARIABLES
Variables can be controlled by
• Random allocation
• Extraneous variables can be controlled by
keeping them constant or eliminating them
A small scale trial run of a research study to test any aspects of the
design, with a view to making improvements.
This should establish whether the design works.
Based on the feedback from the pilot study, researcher can make
Saves time, effort and money.
Opportunity sample- uses easily available participants....Biased
Volunteer sample-uses volunteers.......Biased
Random sample-uses random number technique.....Unbiased
Stratified and quota sample – use subgroups within a population and
a proportionate number of participants selected. In stratified sampling,
random selection of participants leads to more representative sample.
In quota sampling, opportunity sampling is used...biased
Snowball sample- Uses personal contacts of participants....biased
Reliability in different research methods.
In the context of an experimental research it refers to consistency of
In observation method, the extent of agreement between observers is
called inter-rater or inter-observer reliability. Reliability can be improved
In self report methods, the two types of reliabilities are
Internal reliability : the extent to which a test is consistent within itself.
External reliability: consistency over several different occasions.
Inter-interviewer reliability- is the consistency of the outcome of
interviews by different interviewers.
Two assessment methods of reliability: Split-half method and test-retest
ISSUES OF RELIABILITY
ISSUES OF VALIDITY
Validity –whether the results obtained in a study are true/genuine.
Kinds of validity :
Internal: Whether the study did test, what it intended to measure.
External: the extent to which the results of the study can be
generalised to other situations ( ecological validity) and people.
Laboratory experiments are not necessarily low in external validity. If
low in mundane realism, reduces generalisability of the findings.
In observation method, internal validity is affected by observer bias.
In self-report techniques, two ways to assess internal validity are
Face validity: the extent to which the test looks as if it is measuring
what it should measure.
Concurrent validity: assessed by comparing the outcome of a test
with an already established test on the same topic.
ETHICAL CONSIDERATIONS IN PSYCHOLOGICAL RESEARCH
Ethical issues: Informed consent and deception. And Psychological Harm
BPS code of conduct identifies four ethical principles
1. Respect -for the dignity and worth of all persons. This includes: Right to
privacy, confidentiality, informed consent, and right to withdraw. Intentional
deception is acceptable only in some circumstances.
2. Competence- maintaining high standards in research.
3. Responsibility- Protection from harm (physical and psychological) and
4. Integrity- being honest and accurate in reporting.
Ethical guidelines in conjunction with ethical committees used o assess research
Socially sensitive research-potential social consequences for participants.
Ethical issues with Non-humans
Reasons for use of animals in research
Offers greater opportunity for greater control and objectivity;
When it is not possible to use humans;
Moral issues- Whether ‘science at any cost is justifiable’?
Sentience :Do animals experience pain and emotions?
Specieism – Form of discrimination against non-human species.
Animal rights- According to Singer, if animal research can alleviate pain and
suffering, animal research is justifiable. But Regan (1984) argues that no animal
research is acceptable.
Do animals have rights if they have no responsibilities?
Animal research subject to strict legislation (animal acts; BPS guidelines) ----text
Russell and Birch (1959) proposed the three Rs to be followed in animal
research – Reduction (use fewer animals), Replacement (whenever possible
use alternative methods, Refinement (used improved techniques to reduce