validity

• internal validity

  the extent to which the study measures what it claims to measure
• external validity

  the extent to which the findings can be generalised beyond the study
• population validity

  the extent to which the sample can be generalised to the target population
• ecological validity


  the extent to which the study can be generalised to the target population
• temporal validity

  the extent to which the study can be generalised to modern times
• concurrent validity

  the degree to which the results of a test accurately reflect reality

  whether a measure corresponds to another measure that has already been established as valid, such as medical diagnosis