This document discusses various research designs and methods used in psychological research. It describes how psychological research questions are developed and how theories and hypotheses guide research. Observational, experimental, correlational, longitudinal and other research designs are explained along with their strengths and limitations. Key considerations for psychological research like validity, reliability, ethics and statistical analysis are also covered.

1. RESEARCH DESIGNS &RESEARCH DESIGNS &
METHODSMETHODS
Research Methods in PsychologyResearch Methods in Psychology
Desmond Ayim-Aboagye, PhDDesmond Ayim-Aboagye, PhD
(adapted from different sources)(adapted from different sources)

2. Psychological ResearchPsychological Research
QuestionsQuestions
• Does playing violent videogames produceDoes playing violent videogames produce
aggression in children?aggression in children?
• What are the long-term effects of earlyWhat are the long-term effects of early
malnutrition?malnutrition?
• How do children of different ages react toHow do children of different ages react to
a divorce of their parents?a divorce of their parents?

3. Assumptions and Beliefs. TheirAssumptions and Beliefs. Their
OriginOrigin
• Word-of-Mouth FolkloreWord-of-Mouth Folklore
– Friends and relativesFriends and relatives
– Portrayals of children/families on TV/booksPortrayals of children/families on TV/books
– Religious teachingsReligious teachings
– Talk showsTalk shows
• Personal ExperiencesPersonal Experiences
• Expert OpinionsExpert Opinions
• Research EvidenceResearch Evidence

4. Gathering of Research EvidenceGathering of Research Evidence
• Observations of many childrenObservations of many children
• Unbiased observersUnbiased observers
• Reliable, valid methods of measurementReliable, valid methods of measurement
• Careful controlCareful control

5. Theories and their ImportanceTheories and their Importance
• An orderly, integrated set of statementsAn orderly, integrated set of statements
thatthat describesdescribes,, explainsexplains, and, and predictspredicts
behaviorbehavior
• Vital toolsVital tools
– Guide and give meaningGuide and give meaning
– Practical actionPractical action

6. TheoriesTheories  hypotheseshypotheses
• TheoriesTheories  hypotheseshypotheses
– Predictions about behaviorPredictions about behavior
• Research Question vs. HypothesisResearch Question vs. Hypothesis
• Need plan (research design)Need plan (research design) forfor
conducting specific activities (researchconducting specific activities (research
method)method)

7. Examine whether a relationship existsExamine whether a relationship exists
between variablesbetween variables
•Independent VariableIndependent Variable
•Dependent VariableDependent Variable
– Does eating candy produce hyperactivity?Does eating candy produce hyperactivity?
– Does playing violent videogames produceDoes playing violent videogames produce
aggression in children?aggression in children?
– Does drinking wine lower your risk for heartDoes drinking wine lower your risk for heart
disease?disease?
– Does exposure to smoke increase the risk ofDoes exposure to smoke increase the risk of
SIDS?SIDS?

8. STATISTICSTATISTIC
• Statistical SignificanceStatistical Significance
• Reliability – consistencyReliability – consistency
• ValidityValidity
– External/ecological validityExternal/ecological validity
– Internal validityInternal validity

9. Correlational ResearchCorrelational Research
• The Correlational DesignThe Correlational Design
– 2 or more variables meaningfully related2 or more variables meaningfully related
– Correlation coefficient (r)Correlation coefficient (r)
• +1.00 to -1.00+1.00 to -1.00
• Sign indicates directionSign indicates direction
– Positive (+)Positive (+)
– Negative (-)Negative (-)

10. •Figure 1.2 Plot of a hypothetical positive correlation between the amount of violence that children
see on television and the number of aggressive responses they display. Each dot represents a
specific child who views a particular level of televised violence (shown on the horizontal axis) and
commits a particular number of aggressive acts (shown on the vertical axis). Although the
correlation is less than perfect, we see that the more acts of violence a child watches on TV, the
more inclined he or she is to behave aggressively toward peers.

11. Correlational ResearchCorrelational Research
• Correlational studiesCorrelational studies ≠≠ causation.causation.
– Causal direction unknownCausal direction unknown
– Could be due to a third,Could be due to a third,
unmeasured (unmeasured (confoundingconfounding) variable) variable

12. Experimental DesignExperimental Design
• Cause/effectCause/effect
• Systematically manipulate a variableSystematically manipulate a variable
• Random assignmentRandom assignment
– Control groupControl group
– Experimental/treatment group(s)Experimental/treatment group(s)
• Hold conditions constantHold conditions constant
– Eliminate threat of confounding variablesEliminate threat of confounding variables

13. Field ExperimentField Experiment
• Natural settingNatural setting
• Example in text: Belgian delinquents livingExample in text: Belgian delinquents living
in minimum-security institution forin minimum-security institution for
adolescent boysadolescent boys
• Swedish open prisons where prisonersSwedish open prisons where prisoners
can move out and incan move out and in

14. •Figure 1.3 Mean physical aggression scores in the evening for highly aggressive (HA)
and less aggressive (LA) boys under baseline conditions and after watching violent or
neutral movies. ADAPTED FROM LEVENS ET AL., 1975.

15. Field ExperimentField Experiment
• May not be aware that they areMay not be aware that they are
participatingparticipating

16. Field Experiment (cont.)Field Experiment (cont.)
• Study the effects of malnutrition orStudy the effects of malnutrition or
sensory deprivation on infant motorsensory deprivation on infant motor
development.development.
• Volunteers?Volunteers?

17. Natural/Quasi-ExperimentNatural/Quasi-Experiment
• Naturally occurring events (e.g., DavidNaturally occurring events (e.g., David
Koresh and his sect in USA beingKoresh and his sect in USA being
confronted by FBI)confronted by FBI)
• No manipulation of variablesNo manipulation of variables
• No random assignmentNo random assignment

18. •Table 1.4 Strengths and Limitations of General Research Designs

19. Self-Report MethodologiesSelf-Report Methodologies
• Interviews/QuestionnairesInterviews/Questionnaires
– Unstructured to structuredUnstructured to structured
– Difficult with childrenDifficult with children
• Clinical MethodClinical Method
– Can ask follow-up questions specific toCan ask follow-up questions specific to
individual being interviewed (thus, lessindividual being interviewed (thus, less
structured)structured)

20. Self-Report MethodologiesSelf-Report Methodologies
• LimitationsLimitations
– Honesty/accuracyHonesty/accuracy
– Interpretation of questionsInterpretation of questions
– Use with childrenUse with children
• StrengthsStrengths
– Efficient (large amounts of data, short amountEfficient (large amounts of data, short amount
of time)of time)
– Confidentiality improves accuracyConfidentiality improves accuracy

21. Observational MethodologiesObservational Methodologies
• Naturalistic ObservationNaturalistic Observation
– Observations in common, everyday (i.e.,Observations in common, everyday (i.e.,
natural) settingsnatural) settings
– Strengths: easy, behavior is naturalStrengths: easy, behavior is natural
• Thus _________ validity is high…Thus _________ validity is high…
– Limitations: frequency of behavior; reactivityLimitations: frequency of behavior; reactivity

22. Observational MethodologiesObservational Methodologies
• Structured ObservationsStructured Observations
– Laboratory settingLaboratory setting
– Set up a scenarioSet up a scenario
– Strengths: same environment, attempt to elicitStrengths: same environment, attempt to elicit
low frequency behaviorslow frequency behaviors
– Limitations: external validity?Limitations: external validity?

23. Case StudyCase Study
• a detailed portrait of a singlea detailed portrait of a single
individual; can also describe groupsindividual; can also describe groups
– Strength – depthStrength – depth
– LimitationsLimitations
• Difficult to compareDifficult to compare
• GeneralizabilityGeneralizability
• Observer biasObserver bias

24. EthnographyEthnography
• Collect data by living within the culturalCollect data by living within the cultural
community for an extended periodcommunity for an extended period
– Strengths: understanding cultural conflictsStrengths: understanding cultural conflicts
and impacts on developmentand impacts on development
– Limitations: subjective, may not beLimitations: subjective, may not be
generalizablegeneralizable

25. Psychophysiological MethodsPsychophysiological Methods
• Examine relationship betweenExamine relationship between
physiological responses and behaviorphysiological responses and behavior
– Heart Rate – compared to baseline, decreaseHeart Rate – compared to baseline, decrease
may indicate interestmay indicate interest
– EEG – brain wave activity, showing arousalEEG – brain wave activity, showing arousal
states; stimulus detectionstates; stimulus detection
• StrengthsStrengths
– Can examine behaviors in infants/youngCan examine behaviors in infants/young
children before they can self-reportchildren before they can self-report

26. Psychophysiological MethodsPsychophysiological Methods
• Limitations?Limitations?
– High degree of inferenceHigh degree of inference
– Change in physiology due to stimuli?Change in physiology due to stimuli?

27. •Table 1.3 Strengths and Limitations of Seven Common Research Methods

28. Designs for Studying DevelopmentDesigns for Studying Development
• Longitudinal DesignLongitudinal Design
– Same participants over timeSame participants over time
• Can assess stabilityCan assess stability
• Can identify trendsCan identify trends
• Can help understand individual differencesCan help understand individual differences

29. Designs for Studying DevelopmentDesigns for Studying Development
• Longitudinal Design (con’t)Longitudinal Design (con’t)
– LimitationsLimitations
• Costly and time-consumingCostly and time-consuming
• Selective attritionSelective attrition
• Practice effectsPractice effects
• Cohort effectsCohort effects

30. Designs for Studying DevelopmentDesigns for Studying Development
• Cross-sectional DesignCross-sectional Design
– Groups of people of differing ages (althoughGroups of people of differing ages (although
sometimes the same age…) studied at onesometimes the same age…) studied at one
point in timepoint in time
– Strengths?Strengths?
• Efficient (time & money), no practice effects orEfficient (time & money), no practice effects or
attritionattrition
– Limitations?Limitations?
• Information on individual change is not availableInformation on individual change is not available
• Confound age and cohort effectsConfound age and cohort effects

31. •Figure 1.5 Example of a sequential design. Two samples of children, one born in 1998, and one born in 2000
are observed longitudinally between the ages of 6 and 12. The design permits the investigator to assess cohort
effects by comparing children of the same age who were born in different years. In the absence of cohort effects,
the longitudinal and cross-sectional comparisons in this design also permit the researcher to make strong
statements about the strength and the direction of any developmental changes.

32. Designs for Studying DevelopmentDesigns for Studying Development
• Microgenetic DesignMicrogenetic Design
– Illuminate processes that promoteIlluminate processes that promote
developmental changedevelopmental change
• Repeatedly expose children ready for aRepeatedly expose children ready for a
developmental change to experiences thought todevelopmental change to experiences thought to
produce that changeproduce that change
• Monitor behavior as it changesMonitor behavior as it changes

33. Designs for Studying DevelopmentDesigns for Studying Development
• Microgenetic Design (con’t)Microgenetic Design (con’t)
– StrengthsStrengths
• Able to see the process of changeAble to see the process of change
– LimitationsLimitations
• Time consumingTime consuming
• Repeated observationsRepeated observations

34. Table 1.5 Strengths and Limitations of Four Developmental Designs

35. • Questions and DesignsQuestions and Designs
A researcher is interested in whether there is a relationship between theA researcher is interested in whether there is a relationship between the
sporting events in which siblings choose to engage. This researcher sent asporting events in which siblings choose to engage. This researcher sent a
survey to 500 different families and asked parents to write down the age ofsurvey to 500 different families and asked parents to write down the age of
each child and to list in which sports each child participated. Theeach child and to list in which sports each child participated. The
researcher collected all of the surveys and examined whether there was aresearcher collected all of the surveys and examined whether there was a
relationship between siblings’ choice of sports.relationship between siblings’ choice of sports.

36. • ..
• A researcher is interested in whether drinking water right before bedA researcher is interested in whether drinking water right before bed
increases the likelihood that children will wet the bed at night. Theincreases the likelihood that children will wet the bed at night. The
researcher recruits 50 5-year-old children to participate in her study.researcher recruits 50 5-year-old children to participate in her study.
Twenty-five children are given two glasses of water two hours before theirTwenty-five children are given two glasses of water two hours before their
bedtime (one glass per hour) and twenty-five children are prohibited frombedtime (one glass per hour) and twenty-five children are prohibited from
receiving liquids within two hours of their bedtime. The researcher collectsreceiving liquids within two hours of their bedtime. The researcher collects
information from the parents of the children participating for one week –information from the parents of the children participating for one week –
parents are telephoned and asked to report whether the child wet the bedparents are telephoned and asked to report whether the child wet the bed
each nighteach night

37. • A researcher was interested in how children learn how to settleA researcher was interested in how children learn how to settle
disagreements with peers. The researcher talked to his 5-year-old daughterdisagreements with peers. The researcher talked to his 5-year-old daughter
and asked her to describe how she interacted with her peers. Theand asked her to describe how she interacted with her peers. The
researcher then read a few stories to his daughter about children her ageresearcher then read a few stories to his daughter about children her age
who got into disagreements and asked her what she would do in thatwho got into disagreements and asked her what she would do in that
situation. The researcher continued to interview his daughter like this forsituation. The researcher continued to interview his daughter like this for
five years.five years.

38. • A researcher was interested in whether the construct of helplessness (e.g.,A researcher was interested in whether the construct of helplessness (e.g.,
low persistence, negative affect, negative self-evaluations) is similar inlow persistence, negative affect, negative self-evaluations) is similar in
toddlers, preschoolers, and older children. The researcher recruited atoddlers, preschoolers, and older children. The researcher recruited a
group of 2-year-olds and a group of 4-year-olds and brought them into agroup of 2-year-olds and a group of 4-year-olds and brought them into a
playroom setting. The children were videotaped playing with impossibleplayroom setting. The children were videotaped playing with impossible
puzzles and “helpless” behaviors were measured. The children werepuzzles and “helpless” behaviors were measured. The children were
brought back two years later (the first group of children was then 4 and thebrought back two years later (the first group of children was then 4 and the
second group was 6) and were given another set of impossible puzzles.second group was 6) and were given another set of impossible puzzles.
Helpless behaviors were again measured.Helpless behaviors were again measured.

39. • A researcher is interested in whether boys or girls are more aggressiveA researcher is interested in whether boys or girls are more aggressive
when playing with peers. The researcher goes to a playground every daywhen playing with peers. The researcher goes to a playground every day
for 5 weeks and watches children playing with one another. The researcherfor 5 weeks and watches children playing with one another. The researcher
records every instance of aggression that he witnesses.records every instance of aggression that he witnesses.

40. • A researcher is interested in whether a mother’s diet during pregnancyA researcher is interested in whether a mother’s diet during pregnancy
influences her baby’s cognitive ability. The researcher finds a group ofinfluences her baby’s cognitive ability. The researcher finds a group of
women who were malnourished during pregnancy and tests their infants’women who were malnourished during pregnancy and tests their infants’
cognitive skills and finds another group of women who were notcognitive skills and finds another group of women who were not
malnourished during pregnancy and gives the same test to their infants.malnourished during pregnancy and gives the same test to their infants.
The researcher then gives all of the children an IQ test when they reach theThe researcher then gives all of the children an IQ test when they reach the
age of 6.age of 6.

41. Examples of ExperimentalExamples of Experimental
Studies in PsychologyStudies in Psychology
• http://
www.simplypsychology.org/milgram.html
• Sherif and Ash Experiment on Conformity
(Social Psychology)
• Experiment on Psychedelic drugs (The
Good Friday) Psychology of Religion
• Experiment Concerning the Good
Samaritan (Psychology of Religion)

42. Ethical ConsiderationsEthical Considerations
• Research Ethics – standards of conduct toResearch Ethics – standards of conduct to
protect participants from harmprotect participants from harm
– Protection from harmProtection from harm
– Benefits to risks ratioBenefits to risks ratio
– Informed consentInformed consent
– ConfidentialityConfidentiality
– Deception/Debriefing/Knowledge of ResultsDeception/Debriefing/Knowledge of Results