In terms of assessment, what does validity measure?

Validity is a crucial concept in assessment, specifically referring to the degree to which a test accurately measures what it intends to measure. When a test is valid, it means that the inferences made from the test scores are appropriate and meaningful for the specific context and purpose for which the test is designed. For example, if a test is designed to measure a child's phonemic awareness, high validity would indicate that the test effectively assesses that specific skill rather than other unrelated abilities.

Considering the other options, while ease of administration, cost-effectiveness, and item complexity may have their own importance in testing, they do not directly pertain to the core purpose of validity. Ease of administration may relate more to practicality than to what is being measured. Cost-effectiveness can be a secondary consideration, but it doesn't speak to whether the test is appropriate for its intended purpose. Complexity of test items can influence a child's ability to succeed on a test, but it also does not address the essential quality of validity in measuring specific constructs or skills accurately.