Methods of Enquiry in Psychology
This domain covers how psychologists gather evidence - goals of enquiry, research designs, sampling and ethics - and the exam tests matching a method to a question and spotting design errors.
Goals and steps
Description, explanation, prediction, control and application. The usual sequence: identify the problem, review literature, frame a hypothesis, choose a design, collect data, analyse, interpret and report.
Methods
- Observation: naturalistic or controlled; participant or non-participant; structured or unstructured. Weaknesses include observer bias and reactivity.
- Experiment: manipulation of the independent variable, measurement of the dependent variable, a control group and random assignment; confounds destroy causal claims.
- Correlation: coefficient from -1 to +1; shows association only.
- Survey and interview: questionnaires, with social desirability bias as a risk.
- Case study: depth rather than generalisability.
- Psychological tests: require reliability, validity and norms.
Ethics
Informed consent, no harm, confidentiality, anonymity, right to withdraw, debriefing and justified use of deception.
Worked example
Hypothesis: noise lowers exam performance. Independent variable = noise level (loud vs quiet); dependent variable = test score; random assignment to conditions; same test and time of day. If the loud group scores lower, causation can be inferred only if no confound (such as prior ability) differed systematically. Reasoning: random assignment makes groups equivalent on average.
Traps
- Reading causation into a correlation.
- Calling a naturalistic observation an experiment.
- Confusing reliability (consistency) with validity (measuring what is intended).
- Omitting operational definitions.