Reliability

• Internal reliability

  • Refers to whether everything is consistent in study
• External reliability

  • Refers to whether research could achieve consisent results across another study or period
• How to make study internally reliable

  • Consisent questions
  • Standardised procedure
  • Environment or conditions the same
• How to assess internal reliability

  • Split half method:

  Split scores in half to measure consistency
• How to assess external reliability

  • Test re-test: Measure stability overtime
  • Inter-rater: To the degree which different raters give same consisent estimates
• Ways to improving reliability in general

  • Conduct a pilot study
  • Scorer reliability
  • Timing
  • Removing items lowering reliability