PSY 239 401 CHAPTER 3 SLIDES

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<ul><li>1.Chapter 3: Personality Psychology as Science: Research Methods The Personality Puzzle Sixth Editionby David C. FunderSlides created by: Tera D. Letzring Idaho State University 2013 W. W. Norton &amp; Company, Inc.1</li></ul> <p>2. Objectives Discuss research methods that are particularly important to personality psychology Discuss the difference between scientific education and technical training Discuss aspects of data quality Discuss common research designs Discuss some statistical issues Discuss research ethics 2013 W. W. Norton &amp; Company, Inc.2 3. Psychologys Emphasis on Methods Psychologists sometimes seem to know more about research methods than about the mind and behavior. Goal: improving hypotheses Question everything, be skeptical, think analytically. 2013 W. W. Norton &amp; Company, Inc.3 4. Scientific Education and Technical Training Technical training Scientific education Question what is already known Learning to explore the unknown Research: the exploration of the unknown 2013 W. W. Norton &amp; Company, Inc.4 5. Quality of Data: Reliability Definition Measurement error Also called error variance The cumulative effect of extraneous influences States versus traits 2013 W. W. Norton &amp; Company, Inc.5 6. Quality of Data: Factors that Undermine Reliability Low precision of measurement The state of the participant The state of the experimenter The environment 2013 W. W. Norton &amp; Company, Inc.6 7. Quality of Data: Enhancing Reliability Be careful Use a standardized procedure or protocol Measure something that is important and engages participants 2013 W. W. Norton &amp; Company, Inc.7 8. Quality of Data: Enhancing Reliability Aggregation Allow random influences to cancel each other out Especially important for predicting behavior Spearman-Brown formula 2013 W. W. Norton &amp; Company, Inc.8 9. Quality of Data: Validity Definition A slippery concept Reliability is necessary but not sufficient for validity. Invokes the idea of ultimate truth 2013 W. W. Norton &amp; Company, Inc.9 10. Quality of Data: Validity Difficulty of measuring a construct Assessing personality is similar to testing a theory. Construct validation Gather as many measurements as possible. Look for the ones that hang together. 2013 W. W. Norton &amp; Company, Inc.10 11. Quality of Data: Generalizability The distinction between reliability and validity is regarded as fuzzy by some. Definition 2013 W. W. Norton &amp; Company, Inc.11 12. Quality of Data: Generalizability Generalizability over participants Gender bias: Women are more likely to volunteer and show up. Shows versus no-shows Cohort effects: the tendency of a group of people living at a particular time to be different in some way from those who lived earlier or later Ethnic and cultural diversity 2013 W. W. Norton &amp; Company, Inc.12 13. Quality of Data: Generalizability The burden of proof Avoid simplistic generalizations to members of other cultures and people in different times (including differences). Those who question the generalizability of a study should propose when, how, and why it is not generalizable. 2013 W. W. Norton &amp; Company, Inc.13 14. Research Design: Case Method Definition Can yield explanations of particular events, general lessons, and scientific principles Case studies of ourselves 2013 W. W. Norton &amp; Company, Inc.14 15. Research Design: Case Method Advantages Describes the whole phenomenon Source for ideas Sometimes necessary for understanding an individual Disadvantages No control Findings must be confirmed by other cases, which is not usually possible. 15 2013 W. W. Norton &amp; Company, Inc. 16. Research Design: Experimental Method Definition: a research technique that establishes the causal relationship between an independent variable (x) and a dependent variable (y) by randomly assigning participants to experimental groups characterized by differing levels of x, and measuring the average behavior y that results in each group 2013 W. W. Norton &amp; Company, Inc.16 17. Research Design: Experimental Method Test differences between groups with statistical tests to determine if the difference is larger than would be expected by chance 2013 W. W. Norton &amp; Company, Inc.17 18. Research Design: Experimental Method Leaders (high power)Leaders assistants (low power) 2013 W. W. Norton &amp; Company, Inc.Rank list of items needed to survive in a lifeboat on the open seaMeasure interpersonal sensitivity18 19. Research Design: Experimental Method F (1, 72) = 4.91, p = .03 2013 W. W. Norton &amp; Company, Inc.19 20. Research Design: Correlational Method Definition Scatter plot Correlation coefficient 2013 W. W. Norton &amp; Company, Inc.20 21. Research Design: Correlational Study Measure powerMeasure interpersonal sensitivityDetermine the relationshipr = .25 2013 W. W. Norton &amp; Company, Inc.21 22. Research Design: Comparing the Experimental and Correlational Methods Both attempt to assess the relationship between two variables. The statistics (with two groups) are interchangeable. The experimental method manipulates the presumed causal variable, and the correlational method measures it. 2013 W. W. Norton &amp; Company, Inc.22 23. Research Design: Comparing the Experimental and Correlational Methods Only experiments can assess causality. Correlational studies: unknown direction of cause; third-variable problem 2013 W. W. Norton &amp; Company, Inc.23 24. Research Design: Comparing the Experimental and Correlational Methods Complications with experiments Uncertainty about what was really manipulated Third-variable problem Can create unlikely or impossible levels of a variable Often require deception Not always possible Experiments are not always better. 2013 W. W. Norton &amp; Company, Inc.24 25. Research Design: Representative Design Frequent concern: representativeness of participants Less frequent, but important, concerns Representativeness across stimuli Representativeness across responses 2013 W. W. Norton &amp; Company, Inc.25 26. Research Design: Representative Design Solution: use a representative design Seldom done because it is expensive and timeconsuming 2013 W. W. Norton &amp; Company, Inc.26 27. Thinking About Representativeness How is the psychology of todays college students different from that of their parents? Would the conclusions of research done with college students apply to their parents? What areas are most likely to be different? 2013 W. W. Norton &amp; Company, Inc.27 28. Thinking About Representativeness Is research done with the predominantly white college students in Western cultures also relevant to members of ethnic minorities or to people who live in other cultures? In what areas would you expect to find the most differences? 2013 W. W. Norton &amp; Company, Inc.28 29. Significance Testing Statistical significance: a result that would only occur by chance less than 5% of the time p-level: probability level of obtaining a result from a statistical test if there really is no difference between groups or no relationship between variables Null-hypothesis significance testing (NHST) 2013 W. W. Norton &amp; Company, Inc.29 30. Significance Testing: Problems with NHST The logic is difficult to describe (and understand). Significant does not necessarily mean strong or important. The criterion for significance is an arbitrary rule of thumb. Chances of significance vary with sample size. 2013 W. W. Norton &amp; Company, Inc.30 31. Significance Testing: Problems with NHST Nonsignificant results are often interpreted as no result. Only provides information about the probability of one type of error Type I error vs. Type II error Cannot really tell you if a result is important 2013 W. W. Norton &amp; Company, Inc.31 32. Correlations and Effect Sizes Effect size definition More meaningful than a significance (p) level Correlation coefficient Can be used for correlational and experimental studies Between -1 and +1 0 = no relationship Positive and negative correlations 2013 W. W. Norton &amp; Company, Inc.32 33. Correlations and Effect Sizes Use for prediction Interpreting correlations Look at the actual size r2 = percent of variance explained; a terrible way to evaluate effect size (p. 92) Binomial Effect Size Display (BESD) 2013 W. W. Norton &amp; Company, Inc.33 34. BESD r = .00 Drug No drugLived 50 50 100 2013 W. W. Norton &amp; Company, Inc.Died 50 50 100100 100 20034 35. BESD r = .30 Drug No drugLived 50 + (r*100)/2 = 65 50 - (r*100)/2 = 35 100 2013 W. W. Norton &amp; Company, Inc.Died 50 - (r*100)/2 = 35 50 + (r*100)/2 = 65 100100 100 20035 36. BESD r = .25 High I.S.Low I.S.62.537.510037.562.5100High power Low power100100200If you are worried about being interpersonally sensitive, do you want to have high power? 2013 W. W. Norton &amp; Company, Inc.36 37. Thinking About Statistical Issues Lets say we find that you score 4 points higher on a conscientiousness test than does another person. Alternatively, imagine that women score 4 points higher on the same test, on average, than men do. In either case, is this difference important? What else would we have to know to be able to answer this question? 2013 W. W. Norton &amp; Company, Inc.37 38. Research Ethics The uses of psychological research Make sure it is not harmful, or at least that the potential harm does not outweigh the potential good. Truthfulness Avoid plagiarism and fabrication of data. 2013 W. W. Norton &amp; Company, Inc.38 39. Research Ethics: Deception Definition Purpose: usually to make the research realistic APA guidelines Review by the Institutional Review Board (IRB) or Human Subjects Committee (HSC) 2013 W. W. Norton &amp; Company, Inc.39 40. Research Ethics: Deception Arguments in favor of deception Informed consent It usually does no harm. Certain topics cannot be investigated without deception. 2013 W. W. Norton &amp; Company, Inc.40 41. Research Ethics: Deception Arguments against deception Informed consent for deception is not possible. When does the deception stop? Harms credibility of psychology Alternative: Investigate topics in the real world. What do you think about deception? Is it justified? 2013 W. W. Norton &amp; Company, Inc.41 42. Clicker Question #1 In order to say that one variable caused another, a researcher must a)calculate the correlation between the variables. b) conduct an experiment. c) construct a BESD. d) use deception. 2013 W. W. Norton &amp; Company, Inc.42 43. Clicker Question #2 In order for data to have a high degree of validity a)they must also have a high degree of reliability. b) they must come from an experiment. c) they must have low generalizability. d)one must know the ultimate truth about the construct being assessed. 2013 W. W. Norton &amp; Company, Inc.43 44. Clicker Question #3 The case method should be used when a)the researcher is especially concerned that the results have high generalizability. b)the researcher wants to establish the cause of a particular behavior. c)the researcher wants to have lots of control. d)there is an individual that the researcher wants to understand as fully as possible. 2013 W. W. Norton &amp; Company, Inc.44 </p>