What does reliability in assessments refer to?

Reliability in assessments refers to the consistency of assessment results over time. When an assessment is reliable, it means that if the same test were administered multiple times to the same group under similar conditions, it would yield similar results each time. This consistency is crucial because it ensures that the assessment measures what it intends to measure without being influenced by external factors or inconsistencies in the testing process.

For example, if a student takes a mathematics assessment today and receives a certain score, and then takes a similar assessment a week later under the same conditions and receives a similar score, we can infer that the assessment is reliable. This reliability is an important aspect of testing because it builds trust in the assessment results, allowing educators to make informed decisions based on those results.

In contrast, the accuracy of test results concerns how well the assessment reflects the true level of student understanding (more aligned with validity), the ability to measure complex skills pertains to the breadth of assessment (often linked to the scope and depth of learning being assessed), and variety in assessment formats refers to the different methods used to evaluate student learning. These factors are important in their own right but do not define reliability.