AQA Psychology A-Level - Year 1 - Research Methods

What is an aim?

A general statement of what the researcher intends to investigate and the purpose of the study.

What is a hypothesis?

A clear, precise and testable statement predicting the relationship between variables and the expected outcome of a study.

What is an experimental method?

A method where the IV is deliberately changed so its effect on the DV can be measured.

What are variables?

Anything that can vary or change within an investigation.

What is operationalisation?

Clearly defining variables in terms of how they can be measured.

What is the dependent variable (DV)?

The variable measured by the researcher; any effect on it should be caused by a change in the IV.

What is the independent variable (IV)?

An aspect of the experimental situation that is manipulated by the researcher, or changes naturally, so its effect on the DV can be measured.

What is a directional hypothesis?

A hypothesis that states the expected direction of a difference or relationship.

When should a directional hypothesis be used?

When past research suggests a particular outcome.

What is a non-directional hypothesis?

A hypothesis that predicts a difference or relationship but does not state its direction.

When should a non-directional hypothesis be used?

When there is little/no previous research or previous research has produced contradictory findings.

What should a good experimental hypothesis include?

Future tense, operationalised IV and DV, the relationship between IV and DV, appropriate wording for the design, and a directional word if it is directional.

What is an extraneous variable (EV)?

Any variable other than the IV that may affect the DV if it is not controlled.

What is a confounding variable?

A type of extraneous variable that varies systematically with the IV.

How can extraneous variables be controlled?

Through methods such as standardisation and randomisation.

What are demand characteristics?

Cues from the researcher or research situation that participants believe reveal the investigation's purpose.

How can demand characteristics affect behaviour?

Participants may guess the aim and change their behaviour, for example trying to please or sabotage the researcher.

What is the 'please-U effect'?

When participants change their behaviour because they want to please the researcher.

What is the 'screw-U effect'?

When participants deliberately change their behaviour to sabotage the experimenter.

How can demand characteristics be reduced?

Through deception, single-blind or double-blind procedures.

What are investigator effects?

Any effect of the investigator's behaviour on the research outcome/DV.

What can cause investigator effects?

Unconscious cues, researcher expectations, participant selection and leading questions.

How can investigator effects be reduced?

Using double-blind procedures, standardisation and randomisation.

What is randomisation?

Using chance methods to control the effects of bias when designing materials or deciding the order of experimental conditions.

How does randomisation help control investigator effects?

It prevents researchers from making choices that could introduce bias.

What is standardisation?

Using exactly the same formalised procedures and instructions for all participants.

Why is standardisation important?

It ensures participants experience the same environment, information and procedures, reducing EVs caused by differences in procedure.

What is a control group?

In an independent groups experiment, participants who receive no treatment and provide a baseline against which the effect of the IV can be measured.

What is experimental design?

The different ways participants can be organised in relation to the experimental conditions.

What is an independent groups design?

A design where participants are allocated to different groups and each group experiences one level of the IV.

What is a strength of independent groups?

There are no order effects because participants only experience one condition.

Why are demand characteristics reduced in independent groups?

Participants experience only one condition, so they are less likely to work out the aim.

What is a limitation of independent groups?

Participant variables may differ between groups and act as EVs.

How can participant variables in independent groups be controlled?

Through random allocation.

Why is independent groups less economical?

Each participant only contributes one result, so more participants are needed.

What is a repeated measures design?

A design where all participants take part in all conditions of the experiment.

What is a strength of repeated measures?

Participant variables are controlled because the same participants take part in every condition.

Why is repeated measures economical?

Fewer participants are needed because each participant contributes results to every condition.

What are order effects?

Extraneous variables arising from the order in which conditions are presented.

What is a practice effect?

An order effect where participants perform better in a later condition because they have practised the task.

What is a boredom effect?

An order effect where participants perform worse in a later condition because they become bored or tired.

What is a continuing effect?

When the effects of one experimental condition continue into a later condition.

How can order effects be controlled in repeated measures?

Through counterbalancing.

What is counterbalancing?

An attempt to control order effects by having half the participants experience conditions in one order and the other half in the opposite order.

What is the ABBA technique?

A form of counterbalancing where participants experience conditions in opposite orders, such as ABBA.

What is random allocation?

Giving participants an equal chance of being allocated to each condition in an independent groups design.

Why is random allocation used?

To help control participant variables between groups.

What is a matched pairs design?

Participants are paired based on variables that may affect the DV, with each member of a pair assigned to a different condition.

How are matched pairs created?

A pre-test is conducted on a variable that may affect the DV, participants are ranked, and similar participants are paired.

Why is random allocation still used in matched pairs?

To prevent the researcher choosing which member of each pair enters each condition.

What is a strength of matched pairs?

It reduces participant variables while also reducing order effects and demand characteristics.

What is a limitation of matched pairs?

Matching participants can be time-consuming and expensive.

Why can matched pairs not completely control participant variables?

Participants can never be matched exactly, so important differences may remain.

What is a laboratory experiment?

An experiment in a highly controlled environment where the researcher deliberately changes the IV, measures the DV and controls EVs.

What is a strength of a laboratory experiment?

High control allows researchers to establish cause and effect and gives high internal validity.

Why are laboratory experiments easier to replicate?

Extraneous variables can be controlled, making the procedure easier to repeat.

What is a limitation of a laboratory experiment?

It can have low mundane realism/external validity because behaviour may be unnatural.

Why might participants behave unnaturally in a laboratory experiment?

They are usually aware that they are being tested.

What is a field experiment?

An experiment in a natural setting where the researcher deliberately changes the IV and measures its effect on the DV.

What is a strength of a field experiment?

High mundane realism/external validity because behaviour occurs in a natural setting.

Why might behaviour be more natural in a field experiment?

Participants may be unaware that they are being studied.

What is a limitation of a field experiment?

There is less control over EVs.

Why can field experiments be difficult to replicate precisely?

The natural setting contains EVs that may change between investigations.

What ethical issue can arise in a field experiment?

If participants are unaware they are being studied, they cannot give informed consent and their privacy may be invaded.

What is a natural experiment?

An experiment where the change in the IV occurs naturally and would have happened even without the researcher.

What is a strength of a natural experiment?

It allows researchers to investigate events that could not be created for practical or ethical reasons.

What is a limitation of a natural experiment?

The naturally occurring event may be uncommon, limiting opportunities for research and generalisation.

Why might participant allocation be a problem in natural experiments?

Participants may not be randomly allocated because the researcher does not control the IV, so groups may differ in other ways.

Why can't natural experiments establish that the IV caused the DV?

The IV is not deliberately changed by the researcher, so other differences may explain the change.

What is a quasi-experiment?

A study where the IV is a pre-existing difference between participants, such as age or gender, that cannot be changed by the researcher.

What is a strength of a quasi-experiment?

If it is controlled, it can have high internal validity and allow cause and effect to be established according to the notes.

What is a limitation of a quasi-experiment?

Participants cannot be randomly allocated to the IV conditions, so EVs may exist.

Why can't a quasi-experiment establish that the IV caused the DV?

The IV is not deliberately changed by the researcher.

What is a population?

The entire group of individuals a researcher is interested in.

What is a target population?

The entire group of people the researcher wants to represent through their research.

What is a sample?

A group of individuals who take part in a research investigation and are drawn from a population.

What is sampling?

The process of selecting individuals from a population to take part in research.

What is sampling bias?

When certain groups are over- or under-represented in a sample, limiting generalisation.

What is generalisation?

The extent to which findings from an investigation can be applied to the wider population.

What is a sampling frame?

A list of all individuals in the target population.

What is random sampling?

A method where every member of the target population has an equal chance of being selected.

How is a random sample obtained?

Obtain a complete list, number everyone, use a random method to select numbers, convert numbers into names and approach those people.

What is a strength of random sampling?

It avoids researcher bias.

What is a limitation of random sampling?

It can be difficult and time-consuming.

Why can random sampling still produce a biased sample?

A small sample may be unrepresentative despite probability making this less likely.

What is systematic sampling?

A method where every nth person is selected from a sampling frame.

How can systematic sampling be made random?

Select the first person randomly, then select every nth person afterwards.

How is n calculated in systematic sampling?

Number in the target population ÷ number wanted in the sample.

What is a strength of systematic sampling?

It avoids researcher bias.

What is a limitation of systematic sampling?

It may produce a biased or unrepresentative sample.

What is stratified sampling?

A method where the sample reflects the proportions of people in different subgroups/strata within the target population.

How is a stratified sample obtained?

Identify strata, calculate the proportion needed from each, then select participants to represent each stratum.

What is a strength of stratified sampling?

It produces a representative sample and reduces sampling bias.

When is stratified sampling particularly useful?

When the numbers of people in different strata are uneven.

What is a limitation of stratified sampling?

Complete representation of the target population is impossible because not every possible difference can be represented.

What is opportunity sampling?

Selecting the people who are most easily available at the time of the study.

Why is opportunity sampling used?

Representative samples of the target population can be difficult to obtain.

What is a strength of opportunity sampling?

It is convenient and economical in terms of time and money.

What are two sources of bias in opportunity sampling?

The sample may come from a specific area/demographic, and the researcher has control over participant selection.

What is volunteer/self-selection sampling?

A sampling method where people select themselves to take part after being invited.