Måttvalidt

Måttvalidt refers to the validity of a measurement instrument, i.e., the extent to which the instrument measures the intended construct and supports meaningful interpretation of results. In research fields such as psychology, education, and health, valid measurements are essential for drawing accurate conclusions. Validity is distinct from reliability; a measure can yield consistent results without accurately capturing the concept being studied.

There are several facets of validity. Content validity assesses whether the instrument covers all relevant aspects of the construct. Face validity refers to the impression that the items seem appropriate and relevant to respondents. Criterion validity evaluates how well a measure correlates with external criteria, including concurrent validity (measures taken at the same time) and predictive validity (future outcomes). Construct validity examines whether the instrument relates to other measures as theory predicts, including convergent validity (related constructs) and discriminant validity (unrelated constructs). In some contexts, ecological validity is considered, focusing on how well results generalize to real-world settings.

Assessing validity involves multiple approaches. Expert judgment and systematic literature reviews help establish content validity. Statistical methods such as factor analysis or item response theory examine the structure and interpretation of items to support construct validity. Correlations with established measures test convergent and discriminant validity, while known-groups comparisons and ROC analysis can inform criterion validity. Measurement invariance testing is used to ensure that the instrument operates similarly across different demographic groups.

Practically, validity is context- and population-specific and can be affected by translation and cultural adaptation. Validity evidence should be reported alongside results, and validity is an ongoing process that may evolve with new data and applications.