In logic, validity refers to the property of an argument whereby if the premises are true then the truth of the conclusion follows by necessity. The use of the term in logic is narrower, relating to the relationship between the premises and conclusion of an argument. It is generally accepted that the concept of scientific validity addresses the nature of reality in terms of statistical measures and as such is an epistemological and philosophical issue as well as a question of measurement.

In psychometrics, validity has a particular application known as test validity: 'the degree to which evidence and theory support the interpretations of test scores' ('as entailed by proposed uses of tests'). face validity, construct validity, etc.) described in greater detail below. Validity is based on the strength of a collection of different types of evidence (e.g. The validity of a measurement tool (for example, a test in education) is the degree to which the tool measures what it claims to measure. The word 'valid' is derived from the Latin validus, meaning strong.

(also referred to as divergent validity)įace validity is a measure of how representative a research project is ‘at face value,' and whether it appears to be a good project.Validity is the main extent to which a concept, conclusion or measurement is well-founded and likely corresponds accurately to the real world. Discriminant validitytests that constructs that should have no relationship do, in fact, not have any relationship.Convergent validity tests that constructs that are expected to be related are, in fact, related.A test designed to measure depression must only measure that particular construct, not closely related ideals such as anxiety or stress. Construct ValidityĬonstruct validity defines how well a test or experiment measures up to its claims. It involves testing a group of subjects for a certain construct and then comparing them with results obtained at some point in the future.Ĭontent validity is the estimate of how much a measure represents every single element of a construct. Predictive validity is a measure of how well a test predicts abilities.Concurrent validitymeasures the test against a benchmark test and high correlation indicates that the test has strong criterion validity.

Criterion ValidityĬriterion Validity assesses whether a test reflects a certain set of abilities. Test validity is an indicator of how much meaning can be placed upon a set of test results. “Could there be an alternative cause, or causes, that explain my observations and results?” Test Validity Internal validity is a measure which ensures that a researcher's experiment design closely follows the principle of cause and effect.

Types of validity and reliability