What refers to the amount of error attributed to differences in test scores?

Reliability refers to the consistency and stability of test scores across multiple administrations or different items measuring the same construct. When discussing the amount of error attributed to differences in test scores, reliability assesses how much of the score variation can be trusted as a true reflection of the construct being measured versus random error. If a test is reliable, it produces similar scores for an individual across different instances, indicating that differences in scores are likely due to true variations in the trait being measured, rather than fluctuations or errors in the test itself. This concept is essential in educational psychology because it ensures that assessments accurately reflect student abilities and knowledge, allowing for dependable interpretations and decisions based on those results.

In contrast, content validity, criterion-related validity, and construct validity address different aspects of assessment quality. Content validity ensures that the test covers the appropriate material and dimensions of the construct, criterion-related validity involves the correlation between test scores and other established measures, and construct validity assesses whether the test accurately measures the theoretical construct it purports to measure. Each of these does not specifically focus on the amount of error attributed to differences in test scores as reliability does.