assessing and improving validity

• the two main ways to assess the validity of research are face validity and concurrent validity
• Face validity is whether a test appears to measure what it is supposed to measure ‘on the face of it.’ This is done by ‘eyeballing’ the measuring instrument or passing it to an expert to check.
• Concurrent validity of a test is demonstrated when the results obtained are very close to, or match, those obtained on another recognised and well-established test measuring the same concept/construct. This is tested by doing a correlation between the scores that participants receive on both tests. If the correlation is strong and positive (i.e. +.8 or above), then it is considered to be a valid test as it has high concurrent validity.
• internal validity is improved by demonstrating a high level of control over variables. Control ensures the researcher is measuring any potential cause and effect relationship between the IV and DV, not the effect of an EV on the DV.
• improving internal validity

  • random allocation -controls participant variables
  • standard procedures -controls extraneous variables
  • counterbalancing -controls order effects
  • single& double blind trials - controls researcher bias and demand characteristics
  • peer review -controls researcher bias
• external validity is improved by demonstrating that findings are generalisable. Replication ensures the cause and effect relationship observed in the original study is not just limited to that one particular experimental/observational set up
• improving external validity


  • replicating findings in multiple settings improves ecological validity
  • replicating findings with diverse groups of people improves population validity
  • replicating historical studies improves temporal validity
  • replicating findings using realistic tasks improves mundane realism (or researchers could use diverse participants/situations the first time)