Professional organizations, such as the American Educational Research Association (AERA), the American Psychological Association (APA), and the National Council on Measurement in Education (NCME) provide standards for sources of validity evidence in educational testing.
The first source of validity evidence is based on test content, which was previously called content validity. Some of the things that makes the NAEP assessments so solid are the test development process; how the frameworks are developed and the qualifications of the individuals involved; how items are developed and the methods through which the assessments are vetted; and how the assessments are shared with various audiences for review and comment. This is all part of NAEP’s content validity evidence.
Content validity is also derived from the item writing procedures, the item tryouts, the bias and sensitivity review procedures, the statistical reviews, the alignment studies, and other related processes. These all constitute validity evidence based on test content.