Understanding Experimental Methods in Psychology: A Comprehensive Guide

1. Experimental Methods Sept 13 & 14 Objective: Students will be able to explain and evaluate the research methods used in psychology. Agenda: • CBM • Reading Check • Finish Approaches notes • Research Methods notes • HW: Research methods chart, essay

2. Reading Quiz • The belief that after an outcome of an event that one could have predicted that particular outcome. • Testable prediction usually implied by a theory. • Fair representation of a population because everyone has an equal chance to participate. • The two elements in an experiment – one is the part being manipulated, while the other is being measured. (Must be in the correct order) • Clear statement of procedures which allows the process to be replicated.

3. Basic Ideas • Goal : Describe, predict, control & explain behaviors • Theory • Hypothesis • Variables • Sampling

4. Naturalistic Observation • Watch ONLY • Used if other methods would be misleading • Large amounts of data • Problems: • Change if known being observed • See what expect

5. Case Studies • Individuals/small groups • Interviews, transcripts, tests • Neuropsychology • Uses: • Raw material • Particular people • Testing ground • Limitations: • Limited evidence • Not representative

6. Surveys • Uses: • Large amounts of data • Limitations: • Validity • Wording • Honesty • Distortion

7. Experimental Method Operational Definition – define exact steps/methods used in research • Controlled by researcher • Independent variable • Item being manipulated • Dependent variable • Item being measured and affected • Control group • Receives no treatment • Experimental group • Receives treatment

8. Experimental Method cont’d • Confounding variable • Any factor that affects the dependent variable in addition to or instead of the independent variable • Random variable • Uncontrolled/uncontrollable factors • Reliability • Validity • Experimenter bias • Unintentional effect that researcher may have on results • Placebo effect • No benefit but helps because believe it will • Double blind design • No one knows who gets what

9. Ex Post Facto • Manipulation has already occurred • Use comparison groups • Use groups that are in tact • Explores possible causes and effects • Focuses first on the effect, then attempts todetermine what caused the observed effect

10. Statistics • Measures of central tendency – typical scores • Mean • Median • Mode • Measures of variability • Range • Standard deviation Calculate the mean, median & mode for the following numbers 4, 3, 7, 2, 5, 4, 4, 8

11. Correlation • Correlation coefficient • Positive Correlation • Negative Correlation • Correlation v. Causality

13. Essay Psychologists use a variety of research methods to study behavior. Three of the main research methods used are • Case study • Correlational Study, and • Experiment • Discuss one advantage of each research method mentioned above. • Discuss one disadvantage of each research method mentioned above. Pretend you are a psychologist who will use each of the three research methods – case study, correlational study, and experiement – to determine the effect of taking vitamin J on improving memory. C.For each method listed above, explain a key characteristic of the basic approach you could use to reach a scientific conclusion about the relationship between taking vitamin J and improving memory. You need not design a complete study.