Research methods and techniques: experiments, self-report, observation and correlation; variables and operationalisation; experimental designs; hypotheses; and the strengths and weaknesses of each method.

What this dot point is asking

OCR puts research methods at the heart of Component 1 and weaves them through every core study, so you must choose an appropriate method, design a valid study and write testable hypotheses. The skills here are tested directly on Component 1 and applied to the studies on Component 2.

The answer

The four research methods

Experiments come in types that trade control against realism. A laboratory experiment manipulates the IV in a controlled setting (high control, high replicability, lower ecological validity). A field experiment manipulates the IV in a natural setting (more realistic, harder to control extraneous variables). A quasi-experiment uses a naturally occurring IV that the researcher cannot manipulate, such as age or sex (no random allocation, so cause and effect is weaker).

Variables and operationalisation

Experimental designs

• Independent groups. Different participants in each condition. No order effects, but participant variables may differ between groups (reduced by random allocation).
• Repeated measures. The same participants in every condition. Controls participant variables and needs fewer people, but risks order effects (practice, fatigue), countered by counterbalancing.
• Matched pairs. Different participants matched on key variables (for example IQ or age). Controls participant variables without order effects, but matching is time-consuming and never perfect.

Hypotheses

Examples in context

Example 1. Choosing between a lab and a field experiment. Suppose a researcher wants to study helping behaviour. A laboratory study would let them control exactly who is present and what the victim says, giving high internal validity, but participants may behave differently because they sense they are being observed. A field experiment, like staging an emergency in a public place, captures realistic helping but cannot control bystander numbers or who happens to be passing. The choice trades control (lab) against ecological validity (field), and the right answer depends on which threat matters more for the research aim.

Example 2. When a quasi-experiment is the only option. To compare memory in younger and older adults, age cannot be manipulated or randomly allocated, so the study must be a quasi-experiment using a naturally occurring IV (age group). This means any difference found could reflect confounding variables that correlate with age, such as years of education or health, rather than age itself. Recognising this limit on causal inference is exactly the evaluation OCR rewards.

Try this

Q1. Distinguish between an independent variable and a dependent variable, using an example. [3 marks]

• Cue. The IV is manipulated (for example, words as pictures or text) and the DV is measured (number of words recalled); both must be operationalised.

Q2. Explain one weakness of a laboratory experiment. [2 marks]

• Cue. Low ecological validity, because the artificial controlled setting may produce behaviour that does not generalise to everyday life.

Q3. Write a non-directional hypothesis for a study comparing test scores in quiet versus noisy rooms. [3 marks]

• Cue. There will be a significant difference in test scores out of 20 between participants tested in a quiet room and those tested in a noisy room.