CDISC-Gloss – Establishing from qualitative research the extent to which the clinical outcome assessment (COA) instrument measures the concept of interest including evidence that the items and domains of an instrument are appropriate and comprehensive relative to its intended measurement concept, population, and use.
[NIH-FDA BEST (Biomarkers, Endpoints, and other Tools) Resource, https://www.ncbi.nlm.nih.gov/books/NBK338448/] See also Validation.