1. Unit 2: Research Methods: Thinking Critically with Psychological Science

2. Did We Know It All Along? Hindsight Bias
“I knew it all along”
“Out of sight, out of mind”
“Absence makes the heart grow fonder”

3. Overconfidence Overconfidence
together with hindsight bias, can lead to overestimate our intuition

4. The Scientific Attitude
three main components
curious eagerness
skeptically scrutinize competing ideas
open-minded humility before nature

5. Critical Thinking Critical Thinking “smart thinking” four elements
examines assumptions
discerns hidden values
evaluates evidence
assesses conclusions

6. scientific investigation
5 steps:
(1) form a testable hypothesis
(2) select research method, design study
(3) collect the data
(4) analyze data, draw conclusions
(5) report the findings

7. How Do Psychologists Ask and Answer Questions?

8. The Scientific Method Theory Hypothesis Operational Definition
more than a “mere hunch”
Hypothesis
can be confirmed or refuted
Operational Definition
Replication (repeat)

10. Description The Case Study
suggest further study
cannot discern general truths
cross-sectional studies
longitudinal studies

11. Description The Survey
looks at many cases at once in less depth
word effects
random sampling
representative sample

12. Description The Survey
Sampling
Population
Random Sample

13. Description Naturalistic Observation
describes behavior
does not explain behavior
reactivity

14. Experiment
a research method in which the investigator manipulates a variable under carefully controlled conditions and observes whether any changes occur in a second variable as a result
variables: any measurable conditions, events, characteristics, or behaviors that are controlled and observed in a study

15. (3) Do troops of baboons display territoriality?
Which research method would be optimal for investigating the following questions about behavioral processes? Choose from (a) experiment, (b) naturalistic observation, (c) case study and (d) survey.
(1) Are people’s attitudes about nuclear disarmament related to their social class or education?
(2) Do people who suffer from anxiety disorders share similar early childhood experiences?
(3) Do troops of baboons display territoriality?
(4) Can the presence of food-related cues (delicious-looking desserts in advertisements) cause an increase in the amount of food people actually eat?

16. Correlation Correlation (correlation coefficient)
how well does A predict B
positive versus negative correlation
strength of the correlation
-1.0 to +1.0
scatterplot

17. Correlation
illustration of a range of possibilities

18. Correlation
scatter plot for height an temperament: data from 20 people (each represented by a data point) revels an upward slope, indicating a positive correlation.
The considerable scatter of the data indicates that the correlation is much lower than +1.0 (perfect positive correlation)
perfect correlation occurs rarely in the world
a correlation is positive if 2 sets of scores tend to rise or fall together (perfect positive, perfect negative, [both are direct] and inverse)
negative correlation – says nothing about strength – a weak correlation, indicating little relationship, has a coefficient near zero

19. Correlation
looking only at the blue column, would be very difficult to detect relationship – statistical illumination
here, moving from left to right, the upward slope of the cluster of points shows that the points tend to rise together
in fact, the correlation here is moderately positive (+0.63)

20. Correlation

21. Correlation

22. Correlation

23. Correlation Correlation and Causation
correlation helps predict
does not imply cause and effect

25. Correlation Illusory Correlations
perceived non-existent correlation
a random coincidence

26. Correlation Perceiving Order in Random Events
comes from our need to make sense out of the world
coin flip
poker hand

27. Experimentation Experiment can isolate cause and effect
control of factors
manipulation of the factor(s) of interest
hold constant (“controlling”) factors

28. Experimentation Random Assignment
eliminates alternative explanations
different from random sample

29. Experimentation Random Assignment
Blind (uninformed)
Single-Blind Procedure
Double-Blind Procedure
Placebo Effect

30. Experimentation Random Assignment
Groups
Experimental Group
receives the treatment (independent variable)
Control Group
does not receive the treatment

31. Experimentation Independent and Dependent Variables
independent Variable
confounding variable
effect of random assignment on confounding variables
dependent Variable
what is being measured

32. Experimental Design

33. Comparing Research Methods

34. Statistical Reasoning in Everyday Life

35. Describing Data Measures of Central Tendency
Mode (occurs the most)
Mean (arithmetic average)
Median (middle score)

36. Describing Data Measures of Variability
Range
Standard Deviation

37. Describing Data Measures of Variability
Normal Curve (bell shaped)

38. Making Inferences When Is an Observed Difference Reliable?
Representative samples are better than biased samples
Less-variable observations are more reliable than those that are more variable
More cases are better than fewer

39. Making Inferences When Is a Difference Significant?
Statistical significance
The averages are reliable
The differences between averages is relatively large
Does imply the importance of the results

40. Frequently Asked Questions about Psychology

41. Psychology Applied
Can laboratory experiments illuminate everyday life?
The principles, not the research findings, help explain behavior

42. Psychology Applied Does behavior depend on one’s culture and gender?
Influence of culture on behavior
Gender
More similarities than differences

43. Ethics in Research Ethics in human research Informed consent
Protect from harm and discomfort
Maintain confidentiality
Debriefing

44. APA Ethical Guidelines for Research
(1) A subject’s participation in research should be voluntary and based on informed consent.
(2) Participants should not be exposed to harmful or dangerous research procedures.
(3) If an investigation requires some deception of participants (about matters that do not involve risks), the researcher is required to explain and correct any misunderstanding as soon as possible.

45. APA Ethical Guidelines
(4) Subjects’ rights to privacy should never be violated.

46. Ethics in Research Ethics in animal research
Reasons for using animals in research
Safeguards for animal use

47. STUDY 1
A researcher announces that he will be conducting an experiment to investigate the detrimental effects of sensory deprivation on perceptual-motor coordination. The first 40 students who sign up for the study are assigned to the experimental group, and the next 40 who sign up serve in the control group. The researcher supervises all aspects of the study’s execution.

48. Study 1 cont.
Experimental subjects spend 2 hours in a sensory deprivation chamber, where sensory stimulation is minimal. Control subjects spend 2 hours in a waiting room that contains magazines and a TV. All subjects then perform a ten 1-minute trials on a pursuit-rotor task that requires the to try to keep a stylus on a tiny rotating target. The dependent variable is their average score on the pursuit-rotor task.

49. What flaws are apparent in the study?
sampling bias _____
placebo effects ______
distortions in self-reports _______
confounding of variables _______
experimenter bias _________

50. Study 2
a researcher wants to know whether there is a relationship between age and racial prejudice. She designs a survey in which respondents are asked to rate their prejudice against 6 different ethnic groups. She distributes the survey to over 500 people of various ages who are approached at a shopping mall in a low-income, inner-city neighborhood.

51. The End