In educational measurement, what does "validity" refer to?

Validity in educational measurement is a crucial concept that refers to the extent to which a test accurately measures what it claims to measure. When a test is valid, it ensures that the conclusions drawn from the test scores are sound and meaningful in relation to the specific construct being evaluated.

For instance, if a math test is designed to assess students' understanding of basic arithmetic operations, its validity would be established if the questions effectively cover those specific operations and do not inadvertently assess unrelated skills, such as reading comprehension. In this way, validity is a benchmark that determines whether the test results can be trusted to reflect students' true abilities or knowledge in that area.

This concept contrasts with other aspects of testing such as reliability, which pertains to the consistency of the test results over time or across different groups of test-takers. While reliability is important, a test can be highly reliable yet still not be valid if it does not accurately measure what it is supposed to measure. Therefore, in the context of educational assessments, establishing validity is essential for ensuring that educational decisions are based on accurate data regarding student learning.