Validity

Validity is a comprehensive construct that deals with different aspects of test design and use. Through validity, test designers search for evidence for the adequacy of language samples used, the soundness of the instrument's structure, as well as additional external evidence that can justify a certain interpretation of a test's scores. Test content (content validity), the format, and the appearance of the instrument (face validity), the way the newly‐designed test correlates with existing valid instruments (empirical validly), and the theoretical justifications behind the meaning of its scores (construct validity) are among the key issues that are included in any serious discussion of validity.