Validiteetin

Validity, or validiteetti in Finnish, is the extent to which a measurement, test, or argument measures what it is intended to measure or supports the claims it makes. The genitive form validiteetin is used in Finnish to indicate possession or relation, such as in phrases like validiteetin arviointi (evaluation of validity).

In research and testing, validity has multiple facets. Content validity assesses whether the instrument covers the full domain of the construct being measured. Construct validity evaluates whether the measure truly reflects the theoretical concept, often supported by factor analyses and relationships with related or disparate constructs. Criterion validity examines how well the measure correlates with external criteria, including concurrent and predictive validity. Internal validity concerns whether a study’s design allows causal conclusions, while external validity concerns the generalizability of findings beyond the study sample.

Face validity is a pragmatic judgment that an instrument appears appropriate, though it is not sufficient on its own for scientific validity. Validity is established through systematic evaluation, including expert review, pilot testing, and statistical analyses such as reliability checks and analyses of convergent and discriminant validity. Triangulation and replication across studies enhance validity.

Limitations include context-dependence and the fact that validity is not absolute. Different studies may require different validity types, and various threats—measurement bias, sampling bias, or misalignment between the construct and the instrument—can undermine validity.

Relation to reliability: reliability is about consistency, while validity concerns accuracy. An instrument may be reliable without being valid, but validity typically depends on achieving adequate reliability to yield meaningful results.