Research Procedures (OCR GCSE Psychology): Revision Note

Standardisation

• Extraneous variables can make results from an investigation less valid

  • Therefore it is important to control them using standardisation and randomisation

• Standardisation means keeping all procedures identical across every condition and participant in a study

  • It ensures that only the IV is responsible for any change in the DV, improving reliability and validity

• Standardisation involves:

  • giving the same instructions to all participants

  • providing an identical briefing (before the procedure) and debriefing (after the procedure)

  • keeping the number of participants per condition equal (e.g., 20 participants in each group if the total sample is 40)

  • running each condition for the same length of time (e.g. 15 minutes per condition, unless time is part of the IV)

  • using identical materials, unless the materials themselves are necessary to change the IV (e.g. learning a poem underwater vs. on land)

• Standardisation is important in psychological research as:

  • it allows research to be replicated, which means the findings can be checked for consistency

  • it contributes to a study’s reliability, as consistent procedures make it more likely that the same results would be found again

Randomisation

• Randomisation refers to the deliberate avoidance of bias by making decisions randomly, or by chance, wherever possible

  • It helps ensure that the research remains objective and unbiased

• Randomisation can involve:

  • randomly assigning participants to each condition of the IV (e.g. names drawn from a hat)

  • presenting lists of words, numbers, or images in a random order to avoid researcher bias

• However, true randomisation can sometimes lead to uneven groupings

  • E.g. one condition ending up with all female participants or similar words appearing together

Randomisation in a repeated measures design

• Repeated measures is an experimental design where all participants experience every condition

  • This means that random allocation to conditions isn’t possible

• Instead, researchers use counterbalancing to control for order effects, e.g.,

  • Half of the participants complete Condition A, then Condition B

  • The other half completes Condition B, then Condition A

Evaluation of procedures used in research

Strengths

• High control over procedures increases reliability and helps demonstrate a cause-and-effect relationship between IV and DV

• Standardised and randomised methods allow studies to be replicated, strengthening the credibility of theories (e.g., Asch’s conformity study was successfully replicated across many countries)

Weaknesses

• High control can reduce validity, especially ecological validity, because settings and tasks may be artificial

• Artificial or repetitive tasks can produce demand characteristics, where participants guess the aim and change their behaviour, reducing the validity of results