AQA Psychology A-level - Research methods

Aim

Indication of why the study is taking place

Coding

Categorising (usually qualitative) data

Content Analysis

Method for changing qualitative data into quantitative data

Continuous Data

There are no gaps between the measurements

Correlational Analysis

This shows the strength of a relationship between two variables

Counter-Balancing

Half the participants do Task A followed by Task B, while the other half do Task B followed by Task A, thus cancelling out order effects

Demand Characteristics

The participants guess the purpose of the experiment and change their behaviour, which could affect the findings

Directional Hypothesis

A testable statement which predicts whether the IV will improve or have a detrimental effect on the DV

Discrete Data

There are gaps between the scores

Double Blind

Neither the participants nor the investigator know the purpose of the study

Ecological Validity

The experiment is like a real-life setting

Experimental Condition

Situation imposed on the participant by the experimenter

Hypothesis

A testable statement which predicts what might happen

Independent Groups Design

Different participants are used in each of the conditions

Internal Validity

The IV caused the DV

Interval Data

The data is ordered with equal intervals between the measurements (e.g. time)

Interviews

The experimenter asks questions in a face-to-face situation

Investigator Effects

The influence that the investigator has on the participants based on the investigator's appearance, accent, personality, etc.

Laboratory Experiment

Takes place in a controlled environment, where the IV is manipulated and the DV is measured

Matched Pair Design

Different participants, with similar (or matched) traits, are compared across the two conditions

Mean

All the scores are added and divided by the number of scores, this is the arithmetic average

Measures of Central Tendency

The mean, median and mode

Measures of Dispersion

Range and Standard Deviation

Median

The middle or central score once the data is ranked

Mode

This is the most frequently occurring number in the data

Negative Correlation

As one variable increases, the other decreases

Nominal Data

Observations are put into named categories

Non-Directional Hypothesis

A testable statement which predicts that the IV will influence the DV but not whether it will improve it or have a detrimental effect on it

Null Hypothesis

This predicts that any results from the experiment occurred by chance

Order Effects

These occur when the first task a participant is engaged in influences the second task. Task A may act as practice for Task B and, therefore, make Task B easier. Order effects are overcome by counter-balancing.

Ordinal Data

The data is ordered (e.g. a rating scale)

Operationalise

Variables are operationalised to indicate the measurement or units which were used

Opportunity Sampling

The selection of participants from those who are readily available

Parametric Statistics

These assume that the population in the research sample falls in a normal distribution

Pilot Study

A small scale study conducted before beginning the main study, it allows the experimenter to a) test equipment and techniques b) check the feasibility of the experiment

Placebo

Substance or treatment of no known value used on a control group

Placebo Effect

The improvement demonstrated in the control group due to the administration of a substance or treatment of no known value

Positive Correlation

As one variable increases, so does the other variable

Qualitative Data

Deals with experiences, description and meanings of the participants involved

Quantitative Data

Numerical data

Questionnaire

A pre-set list of questions

Random Sampling

Every member of the target population has an equal chance of being selected

Range

The difference between the highest and the lowest scores

Rapport

Good relationship created between experimenter and participant

Reliability

Consistency

Repeated Measures

The same participants take part in all conditions

Replication

Repeating an experiment to check test-retest reliability

Sampling

The selection of participants

Semi-structured Interviews

The topic area of interest has been set out in advance by the experimenter, some of the questions may already have been pre-set, but they do not necessarily need to be followed

Single Blind

The participants do not know the purpose of the study

Skewed Data

This is data in which some very high or low scores are present

Standard Deviation

Variance from the mean

Structured Interviews

These are sometimes referred to as "formal interviews", a pre-set lit of questions which the experimenter reads to the participant

Test-retest Reliability

The experiment is run again in exactly the same way so that the results can be compared, if there is reliability, the results will show consistency across the experiments

Unstructured Interviews

These are sometimes referred to as "informal interviews", the topic will have been predetermined by the experimenter, but the questions and direction of the interview have not

Validity

Does the test or experiment measure what it is supposed to measure?

Volunteer Sampling

This is sometimes called "self-selecting sampling", the participants volunteer or choose themselves for the experiment