Methods of Enquiry in Psychology
This domain tests the research process: formulating hypotheses, operationalising variables, choosing a method, and judging reliability, validity and ethics.
Goals and variables
Psychology aims at description, explanation, prediction, control and application. An independent variable is manipulated; a dependent variable is measured; extraneous variables are held constant; a confound varies with the IV. Operational definitions make constructs measurable (e.g., memory = words recalled after 30 seconds).
Methods
- Observation: naturalistic or controlled; participant or non-participant.
- Interview: structured, semi-structured, unstructured.
- Questionnaire/survey: efficient but vulnerable to socially desirable responding.
- Experiment: manipulates the IV; laboratory experiments maximise control, field experiments maximise realism.
- Correlational study: measures association, not causation.
- Case study: deep and idiographic, but weak generalisability.
- Archival research and psychological tests: use existing records or standardised instruments.
Worked example
To test whether sleep deprivation impairs memory, assign participants randomly to 4-hour or 8-hour sleep, then test word recall. IV = sleep duration; DV = recall score; control = same testing time and word list. A correlation between poor sleep and poor recall would not by itself prove causation.
Traps
A correlation coefficient near −1 is strong, not weak. Demand characteristics and observer bias distort data. Ethical requirements include informed consent, confidentiality and debriefing after any deception.