the degree to which an experiment measures what is supposed to measure is referred to as
Validity (statistics) Validity is the extent to which a concept,[1] conclusion or measurement is well-founded and corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong. The validity of a measurement tool (for example, a test in education) is considered to be the degree to which the tool measures what it claims to measure; in this case, the validity is an equivalent to accuracy.