Improving Reliability

• How to improve the reliability in observations?

  • Train observers in the coding system/behavioural categories
  • Illustrate what is meant by behavioural categories - using vid clips
  • Check whether operationalisation (behavioural categories)is clear, useable, coherent, complete
  • Give observers lots of practice
  • Pilot study
• How to improve the reliability in questionnaires, tests and interviews?

  Split half

  • Take test
  • Split it in half
  • Do test
  • Correlate scores
  • High reliability = high positive correlation (+0.8)
• General tips?

  • Standardisation: same procedures, same scripts, give the same instructions, behave the same way. For observations and interviews: collect info the same way, same time period
  • Take multiple measurements: take more than one measurement for each participant
  • Develop good measurement systems: precise and accurate measurement systems - Observations: good/accurate behavioural categories, Questionnaires/interviews: questions
  • Pilot studies: check methods works and Ps can use the apparatus can record measurements accurately and retrain them