validity

• Qualitative methods reduce validity

  Uses interpretative validity = the extent researcher's interpretation matches the P's - therefore incoherence of researcher's reporting
• Qualitative methods reduce validity

  • Intervention by researchers - detected in overt observations makes P's behaviour less natural and authentic
  • Broad, overlapping and ambiguous behavioural categories
• Ways to improve validity in questionnaires

  • Lie scale - assess consistency of response and control social desirability bias effects
  • Reassuring Ps that data is anonymised
• Ways to improve validity in experimental research

  • Control groups - better assessment of whether DV changes due to IV
  • Standardise procedures, single-blind or double-blind procedures - minimise participant reactivity and investigator effects
  • Single-blind procedures - reduce demand characteristic effects
  • Double-blind procedures - reduce demand characteristic effects and investigator effects on third party (conducts study w/o knowing main purpose)
• Concurrent validity


  The extent to which results are similar to the ones of another recognised and well-established test
• Ecological validity


  The extent to which a study is realistic or representative of real life
• Event sampling

  Target behaviour or event is first established then the researcher records this event every time it occurs
• External validity

  The extent to which the results of a study can be generalized to other situations/context
• Extraneous variable


  Uninvestigated variable that causes unwanted changes in the DV and doesn't systematically vary with the IV
• Face validity

  Measures whether a test looks like it tests what it is supposed to test
• Historical validity

  The extent to which the findings can be generalised to another time period
• How do qualitative methods enhance validity?


  • More depth and detail that reflects P's reality therefore higher mundane realism (eg in case studies and interviews)
  • Triangulation = using a number