Reliability is a measure of consistency. It is the degree to which student results are the same when they take the same test on different occasions, when different scorers score the same item or task, and when different but equivalent tests are taken at the same time or at different times. Reliability is about making sure that different test forms in a single administration are equivalent; that retests of a given test are equivalent to the original test, and that test difficulty remains constant year to year. Determining whether an assessment is valid and reliable is a technical process that goes well beyond making sure that test questions focus on material covered in state standards. While both of these terms are used by researchers in association with precise statistical procedures, this brief will define assessment validity and reliability in a more general context for educators and administrators.