GCSE Psychology: Research Methods Guide

Types of research method

Psychologists use experiments (manipulating a variable to test cause and effect), observations (watching and recording behaviour), and self-report methods like questionnaires and interviews.

Variables

In an experiment, the independent variable (IV) is what the researcher changes, and the dependent variable (DV) is what is measured as a result. Extraneous variables are other factors that could affect the DV and need to be controlled.

Sampling methods

Random sampling gives every member of a population an equal chance of being selected. Opportunity sampling selects whoever is conveniently available, which is quicker but can introduce bias.

Ethical considerations

Ethical guidelines require informed consent, the right to withdraw, protection from harm, and confidentiality, to ensure participants are treated fairly and respectfully.

Common mistakes

• Mixing up the independent variable (changed) and dependent variable (measured).
• Assuming a larger sample is automatically unbiased, ignoring how it was selected.
• Forgetting ethical guidelines apply throughout a study, not just at the start.