Research Methods

1. Research Methods Psychology 117

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

3. Origins of Assumptions and Beliefs? • Word-of-Mouth Folklore • Friends and relatives • Portrayals of children/families on TV/books • Religious teachings • Talk shows • Personal Experiences • Expert Opinions • Research Evidence

4. Research evidence is valuable because results are: • Observations of many children • Unbiased observers • Reliable, valid methods of measurement • Careful control

5. Theories • An orderly, integrated set of statements that describes, explains, and predicts behavior • Vital tools • Guide and give meaning • Practical action

6. Theories  hypotheses • Predictions about behavior • Research Question vs. Hypothesis • Need plan (research design) for conducting specific activities (research method)

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

8. Statistical Significance • Reliability – consistency • Validity • External/ecological validity • Internal validity

9. Correlational Research • The Correlational Design • 2 or more variables meaningfully related • Correlation coefficient (r) • +1.00 to -1.00 • Sign indicates direction • Positive (+) • 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 Research • Correlational studies ≠ causation. • Causal direction unknown • Could be due to a third, unmeasured (confounding) variable

12. Experimental Design • Cause/effect • Systematically manipulate a variable • Random assignment • Control group • Experimental/treatment group(s) • Hold conditions constant • Eliminate threat of confounding variables

13. Field Experiment • Natural setting • Example in text: Belgian delinquents living in minimum-security institution for adolescent boys

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 Experiment • May not be aware that they are participating

16. Study the effects of malnutrition or sensory deprivation on infant motor development. • Volunteers?

17. Natural/Quasi-Experiment • Naturally occurring events • No manipulation of variables • No random assignment

18. Table 1.4 Strengths and Limitations of General Research Designs

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

20. Self-Report Methodologies • Limitations • Honesty/accuracy • Interpretation of questions • Use with children • Strengths • Efficient (large amounts of data, short amount of time) • Confidentiality improves accuracy

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

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

23. Case Study • a detailed portrait of a single individual; can also describe groups • Strength – depth • Limitations • Difficult to compare • Generalizability • Observer bias

24. Ethnography • Collect data by living within the cultural community for an extended period • Strengths: understanding cultural conflicts and impacts on development • Limitations: subjective, may not be generalizable

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

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

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

28. Designs for Studying Development • Longitudinal Design • Same participants over time • Can assess stability • Can identify trends • Can help understand individual differences

29. Designs for Studying Development • Longitudinal Design (con’t) • Limitations • Costly and time-consuming • Selective attrition • Practice effects • Cohort effects

30. Designs for Studying Development • Cross-sectional Design • Groups of people of differing ages (although sometimes the same age…) studied at one point in time • Strengths? • Efficient (time & money), no practice effects or attrition • Limitations? • Information on individual change is not available • Confound 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 Development • Microgenetic Design • Illuminate processes that promote developmental change • Repeatedly expose children ready for a developmental change to experiences thought to produce that change • Monitor behavior as it changes

33. Designs for Studying Development • Microgenetic Design (con’t) • Strengths • Able to see the process of change • Limitations • Time consuming • Repeated observations

34. Table 1.5 Strengths and Limitations of Four Developmental Designs

35. A researcher is interested in whether there is a relationship between the sporting events in which siblings choose to engage. This researcher sent a survey to 500 different families and asked parents to write down the age of each child and to list in which sports each child participated. The researcher collected all of the surveys and examined whether there was a relationship between siblings’ choice of sports. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

36. A researcher is interested in whether drinking water right before bed increases the likelihood that children will wet the bed at night. The researcher recruits 50 5-year-old children to participate in her study. Twenty-five children are given two glasses of water two hours before their bedtime (one glass per hour) and twenty-five children are prohibited from receiving liquids within two hours of their bedtime. The researcher collects information from the parents of the children participating for one week – parents are telephoned and asked to report whether the child wet the bed each night. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

37. A researcher was interested in how children learn how to settle disagreements with peers. The researcher talked to his 5-year-old daughter and asked her to describe how she interacted with her peers. The researcher then read a few stories to his daughter about children her age who got into disagreements and asked her what she would do in that situation. The researcher continued to interview his daughter like this for five years. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

38. A researcher was interested in whether the construct of helplessness (e.g., low persistence, negative affect, negative self-evaluations) is similar in toddlers, preschoolers, and older children. The researcher recruited a group of 2-year-olds and a group of 4-year-olds and brought them into a playroom setting. The children were videotaped playing with impossible puzzles and “helpless” behaviors were measured. The children were brought 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. Helpless behaviors were again measured. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

39. A researcher is interested in whether boys or girls are more aggressive when playing with peers. The researcher goes to a playground every day for 5 weeks and watches children playing with one another. The researcher records every instance of aggression that he witnesses. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

40. A researcher is interested in whether a mother’s diet during pregnancy influences her baby’s cognitive ability. The researcher finds a group of women who were malnourished during pregnancy and tests their infants’ cognitive skills and finds another group of women who were not 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 the age of 6. • Correlational or Experimental? • Method? • Observation, interview/questionnaire, clinical method, case study, ethnography, psychophysiological • Cross-sectional, longitudinal, or sequential? • IV and DV?

41. Ethical Considerations • Research Ethics – standards of conduct to protect participants from harm • Protection from harm • Benefits to risks ratio • Informed consent • Confidentiality • Deception/Debriefing/Knowledge of Results