Psychology - Research Methods Key Definitions

Key terms from the AS Psychology AQA A specification. 

HideShow resource information
  • Created by: Phil
  • Created on: 31-12-12 13:37

Demand Characteristics

  • A cue that makes participants aware of what the researcher expects to find or how participants are expected to behave. 
1 of 17

Extraneous Variables (EV)

  • Any variable, other than the IV, which may potentially affect the DV and thereby confound the findings. 
  • Order effects, participant variables and situational variables may act as EVs. 
2 of 17

Order Effects

  • In a repeated measures design, an extraneous variable arising from the order in which conditions are presented. 
  • For example, participants do better the second time because the have had practise (practise effect). 
3 of 17

Random Allocation

  • Allocating participants to experimental groups using random techniques. 
4 of 17

Pilot Study

  • A small-scale trial of a study.
  • Run to test any aspects of the design, with a view to making improvements. 
5 of 17


  • A measure of consistency.
  • Internal reliability concerns consistency within a set of scores or items. 
  • External reliability concerns consistency over time such that it is possible to obtain the same results on subsequent occasions when the measure is used with the same thing. 
6 of 17


  • The extent to which a study is and its findings are legitimate or true.
  • Internal validity concerns whether a study has tested what it set out to test. 
  • External validity concerns the degree to which a research finding can be generalised to, for example, other settings (ecological validity), or other groups of people (population validity) and over time (historical validity).
  • Any study that has low internal validity must lack generalisability and therefore also has low external validity. 
7 of 17

Ethical Issues

  • The dilemmas created by the conflict between the needs of the researcher and the rights of the participants.
  • For example, in order to conduct meaningful research it may be necessary to deceive participants, but this affects their right to giving fully informed consent. 
8 of 17


  • The loss of participants from a study over time. 
  • This is likely to leave a biased sample, or a sample that is too small. 
9 of 17

Random Technique

  • Method of selection that ensures each member of the population has an equal chance of being selected. 
  • For example, placing all names in a hat and drawing out the required number.
  • Or by assigning each person a number and using a random number table. 
10 of 17


  • The process of taking a sample.
  • The technique used aims to produce a representative selection of the target population.  
11 of 17

Target Population

  • The group of people that the researcher is interested in. 
  • The group of people from whom a sample is drawn. 
  • The group of people about whom generalisations can be made. 
12 of 17

Volunteer Bias

  • A form of sampling bias. 
  • Occurs because volunteer participants are usually more highly motivated than randomly selected participants. 
13 of 17

Quantitative Data

  • Represent how much, how long, or how many, etc. there are of something. 
  • Data that are measured in numbers or quantities. 
14 of 17

Quantitative Data Analysis

  • Any means of representing trends from numerical data, such as measures of central tendency. 
15 of 17

Levels of Measurement

  • Nominal - Data is measured in separate categories, such as grouping people according to their favourite football team. 
  • Ordinal - Data is ordered in some way, for example, asking people to put a list of football teams in order of liking The 'difference' between each item is not the same, i,.e, the individual may like the first item a lot more than the second, but there might only b a small difference between the items ranked second and third. 
  • Interval - Data is measured using unites of equal intervals, such as when counting correct answers or using any 'public' unit of measurement. 
  • Ratio - There is a true zero point as in most measures of physical quantities. 
16 of 17

Qualitative Data

  • Express the 'quality' of things.
  • This include the descriptions, words, meaning, pictures, texts and so on. 
  • They cannot be counted or quantified but it can be turned into quantitative data by counting the data in categories. 
  • It is sometimes said that qualitative data concern 'thoughts and feelings' - but you can also have quantitative data bout thought and feelings, for example a researcher could ask participants to rate their feelings about a film on a scale of 1 to 5. The difference between quantitative and qualitative research runs much deeper than 'thoughts and feelings'. 
17 of 17


No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Research methods and techniques resources »