• The extent to which a result, such as that of a test, approximates the correct value.
  • The extent to which a test measures what it is intended to measure.
  • The extent to which data is free of errors.
  • The likelihood that a message, file, data, or the like has been unequivocally authenticated.

Health Economics

  • (written as Validity)
    In a general sense, the extent to which a measurement instrument measures what it is designed to measure. More specifically, there are construct validity, convergent validity, criterion validity, discriminant validity, external validity, face validity, internal validity, predictive validity, test-retest validity.


  • noun the fact of being based on sound research and methods which exclude alternative explanations of a result