Question 1

What is the difference between an independent groups design and a repeated measures design?

Accepted Answer

In an independent groups design, different participants are used in each condition of the experiment. This avoids order effects (e.g., practice or fatigue) but requires more participants and may suffer from participant variables (individual differences) affecting results. In a repeated measures design, the same participants take part in all conditions, controlling for participant variables but risking order effects. To counterbalance, you can alternate the order of conditions across participants. The choice depends on the research question and practical constraints.

Question 2

How do I choose the best sampling method for my psychology experiment?

Accepted Answer

The best sampling method depends on your research aims and resources. If you need a representative sample to generalise findings to the target population, stratified or random sampling is ideal, but they can be time-consuming. For quick, convenient data collection, opportunity sampling is common but may introduce bias (e.g., only sampling people available at a certain time). Volunteer sampling (advertising for participants) is useful for sensitive topics but attracts a specific type of person. Always consider the trade-off between representativeness and practicality.

Question 3

What is a confounding variable and how do I control it?

Accepted Answer

A confounding variable is an extraneous variable that systematically varies with the independent variable and affects the dependent variable, making it impossible to determine cause and effect. For example, if you test memory in the morning for one group and afternoon for another, time of day could confound results. To control confounding variables, use random allocation to conditions, standardise procedures (same instructions, environment, timing), and use techniques like counterbalancing or single-blind designs. Pilot studies help identify potential confounds before the main experiment.

Question 4

Why is operationalisation important in psychology research?

Accepted Answer

Operationalisation means defining variables in measurable, specific terms. For example, instead of 'aggression', you might define it as 'number of times a participant presses a button to deliver a loud noise to another person'. This ensures clarity, replicability, and objectivity. Without operationalisation, different researchers might measure the same concept differently, making comparisons impossible. It also allows you to test hypotheses precisely and reduces ambiguity in interpreting results.

Question 5

What are the ethical issues I must consider when planning research?

Accepted Answer

Key ethical issues include informed consent (participants should know what they are agreeing to), deception (if necessary, it must be justified and followed by debriefing), right to withdraw (participants can leave at any time), confidentiality (anonymising data), and protection from harm (avoiding physical or psychological distress). You must also consider the BPS guidelines and gain ethical approval from an ethics committee. For vulnerable groups (e.g., children), additional safeguards like parental consent are required.

Question 6

How do I write a good hypothesis for my psychology coursework?

Accepted Answer

A good hypothesis is a clear, testable statement predicting the relationship between the independent variable (IV) and dependent variable (DV). It should be operationalised, meaning both variables are defined in measurable terms. For example: 'Participants who study in a quiet room will recall significantly more words from a list than those who study in a noisy room.' Use a directional (one-tailed) hypothesis if previous research suggests a direction, or a non-directional (two-tailed) hypothesis if the direction is unclear. Avoid vague terms like 'affects' or 'influences'.

Planning and conducting research

Topic Overview

Key Concepts

What You Need to Demonstrate

Marking Points

Examiner Tips

Common Mistakes

Frequently Asked Questions

Before You Start

Likely Command Words

Ready to test yourself?

Related Topics in OCR A-Level Psychology

Applied psychology (Component 03)

Data recording, analysis and presentation

E2E stub topic

How science works

How to Revise Planning and conducting research — OCR A-Level Psychology

Examiner Tips for Planning and conducting research

Common Mistakes in Planning and conducting research

Key Marking Points