Content-Related Test Validity

A Content-Related Test Validity is a Test Validity that refers to which extent a measure represents all facets of a given construct.

AKA: Content Validity, Logical Validity.
Content:
- It is usually used as test validity that assesses content knowledge.
- It can also refer to which a variable (e.g. a rating scale, index) measures what it is supposed to measure.
- It can be measured as a Content Validity Ratio or Content Validity Index.
- It can be subcategorized into Face Validity and Construct Validity.
Example(s):
- an academic achievement test is considered content valid if and when (a) the curriculum universe has been defined (called the “content domain") and (b) the test adequately samples that universe.
- …
Counter-Example(s):
See: Psychometrics, Subject Matter Expert, Content Domain, Statistical Validity, Extraversion, Depression, Affective, Behavioral, Personality Trait, Internal Validity, External Validity.

References

(Wikipedia, 2021) ⇒ https://en.wikipedia.org/wiki/Content_validity Retrieved:2021-12-4.
- In psychometrics, content validity (also known as logical validity) refers to the extent to which a measure represents all facets of a given construct. For example, a depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension. An element of subjectivity exists in relation to determining content validity, which requires a degree of agreement about what a particular personality trait such as extraversion represents. A disagreement about a personality trait will prevent the gain of a high content validity.

(Wikipedia, 2021) ⇒ https://en.wikipedia.org/wiki/Glossary_of_clinical_research Retrieved:2021-12-5.
- Content validity
  - The extent to which a variable (e.g. a rating scale) measures what it is supposed to measure. (ICH E9)

(Statology, 2021) ⇒ https://www.statology.org/content-validity/ Retrieved:2021-12-5.
- QUOTE: The term content validity refers to how well a survey or test measures the construct that it sets out to measure.
  For example, suppose a professor wants to test the overall knowledge of his students in the subject of elementary statistics. His test would have content validity if:
  - The test covers every topic of elementary statistics that he taught in the class.
  - The test does not cover unrelated topics such as history, economics, biology, etc.

A test lacks content validity if it doesn’t cover all aspects of a construct it sets out to measure or if it covers topics that are unrelated to the construct in any way.

(McLeod, 2013) ⇒ Saul McLeod (2013). "What is Validity?". In: Simply Psychology.
- QUOTE: There are two main categories of validity used to assess the validity of test (i.e. questionnaire, interview, IQ test etc.): Content and criterion.

Types of Validity
CONTENT-RELATED (appropriate content)	CRITERION-RELATED (relationship to other measures)
face validity: does the test appear to test what it aims to test?	concurrent validity: does the test relate to an existing similar measure?
construct validity: does the test relate to underlying theoretical concepts?	predictive validity: does the test predict later performance on a related criterion?

(Lawshe, 1975) ⇒ C. H. Lawshe (1975). "A Quantitative Approach To Content Validity". In: Personnel Psychology, 28(4). A paper presented at Content Validity II, a conference held at Bowling Green State University, July 18, 1975.
- QUOTE: Generally speaking, an academic achievement test is considered content valid if and when (a) the curriculum universe has been defined (called the “content domain") and (b) the test adequately samples that universe.
  (...). Adkins^[1] has this to say about judgments in discussing the content validity approach:
  - In academic achievement testing, the judgment has to do with how closely test content and mental processes called into play are related to instructional objectives.
  - In employment testing, the content validation approach requires judgment as to the correspondence of abilities tapped by the test with abilities requisite for job success.

The crucial question, of course, is, "Whose judgment?" In achievement testing we normally use subject matter experts to define the curriculum universe which we then designate as the “content domain". We may take still another step and have those experts assign weights to the various portions of a test item budget. From that point on, content validity is established by demonstrating that the items in the test appropriately sample the content domain. If the subject matter experts are generally perceived as true experts, then it is unlikely that there is a higher authority to challenge the purported content validity of the test.