1. The Research Process: How We Find Things Out

2. The Scientific Method
What are the components of the scientific method?
Specify a problem
Systematic observation
Data
Replication
Form a hypothesis
Test the hypothesis
Operational definition
Formulate a theory
Test the theory

3. The Scientific Method
What is the relationship between theory, prediction (hypothesis), and data?
Prediction
Theory
Data
Theory development, validation, correction

4. Descriptive Research Naturalistic observation Case studies Surveys
Allows one to see patterns in the real world
Case studies
Focus on a single interesting case in detail
Surveys
A set of questions put to a number of participants about their beliefs, attitudes, preferences, or activities

5. Correlational Research
Studies where the relationships between two or more variables are measured but not manipulated
Examples
Family income and IQ score
Height and shoe size
MAO levels and thrill seeking

6. Correlation
Strength and direction

7. Correlation Research Strength Weakness
Can study variables that cannot be manipulated
Weakness
Correlation does not imply causation

8. Designing Experiments: Independent Variable
The aspect of a situation that is intentionally varied while another aspect is measured
Examples
Amount of practice allowed
Participants randomly assigned so that they receive a drug or placebo
Present visual or auditory stimuli
Temperature of room

9. Designing Experiments: Dependent Variable
The aspect of a situation that is measured while the independent variable is changed
Examples
Number of words recalled
Speed of response
Number of cigarettes smoked
Electrical activity in the brain

10. Designing Experiments: Effects
The difference in the dependent variable that is due to changes in the independent variable
Examples
Drug X impairs short-term memory
Visualization improves athletic performance
Practice improves reading speed

11. Experiments Experimental group Control group Random assignment
Strength
Rigorous control, causal inferences
Weakness
Not all variables can be manipulated

12. Quasi-Experiments Like experiments but without random assignment
Strength
Real-world phenomena that cannot be studied in experiments
Weakness
Lack of control means limited causal inferences

13. Being a Critical Consumer
Reliability
Validity
Face validity
Content validity
Criterion validity
Construct validity

14. Bias and Expectation Response bias Sampling bias
Experimenter expectancy effects
Double-blind design

15. Pseudopsychology
Unsupported opinion pretending to be psychological science
What makes a discipline a science?
Is it the topic of study?
Is it the method of study?
Examples
ESP
Astrology

16. Statistics: Measuring Reality
Benjamin Disraeli: “There are three kinds of lies: lies, damned lies, and statistics.”
Be a critical statistics consumer; know the basics
Two main types of statistics
Descriptive
Inferential

17. Descriptive Statistics
Central tendency
Mean
Median
Mode
Normal distribution

18. Descriptive Statistics
Variability
Range
Standard deviation
Relative standing
Percentile rank

19. Inferential Statistics
Do patterns in measurement reflect true patterns or just chance variation?
Statistical significance
A measured relationship is not simply due to chance
Expressed in terms of probability (p)
Psychologists generally view a finding as “statistically significant” if it has no more than a 5% probability of occurring by chance

20. Inferential Statistics
Sampling
Population
Sample
Sampling error
Meta-analysis
Population
Sample

21. Lying with Statistics Selective reporting
Which statistics are reported and which are omitted?

22. Lying with Graphs
Shortening the Y axis

23. Lying with Graphs
Lengthening the Y axis

24. Lying with Graphs “Tricking” the visual system
Using 3-D graphics to exaggerate size
Changing width with height
Plotting transformed data

25. Reading Research Reports
QALMRI method
Question
Alternatives
Logic of the study
Method
Results
Inferences

26. Writing Research Papers
Introduction
Method
Results
Discussion