Validity

• Validitty


  A measure of whether a study legitimately measures what it claims to measure.
• Internal Validity

  The degree to which a study or test measures what it intended to measure
• External validity 


  The degree to which research findings can be generalised to other situations or people
• External validity can be broken down into 2 main types:

  • Population validity - can the results be generalised beyond the group of people being studied e.g. to the general population.
  • Ecological validity - can the results be generalised beyond the particular setting they were found in e.g. to the real world.
• Issues and Dealing with internal validity

  
  

  EV’s - suggest how the EV’s can be controlled for

  Demand characteristics - use a single blind study

  Researcher bias - use a double blind study

  Social desirability bias - make research anonymous and ensure confidentiality

  Test is inaccurate - conduct a pilot study
• Issues and Dealing with external validity

  Unrepresentative sample - use a more representative sample

  Artificial setting or task  - use a more natural setting or more natural task
• Assessing for validity

  Internal:

  Face - researcher looks

  Content - ask an expert

  Construct - theories

  Concurrent - 2x tests

  External

  Predictive - predict future behavior