What aspect of testing refers to the consistency of assessment outcomes?

The concept that refers to the consistency of assessment outcomes is reliability. This is a crucial aspect of testing because it measures how stable and consistent the results of an assessment are across different administrations, contexts, and populations. In other words, if an assessment is reliable, it will yield similar results under consistent conditions, which is essential for making valid interpretations about a student's knowledge or skills.

For example, if a student takes the same test on different occasions and scores similarly each time, the test is considered reliable. This reliability ensures that the assessment is not heavily influenced by unpredictable factors such as the student's mood, external environment, or even the particular set of questions on that day.

In contrast, the other concepts mentioned do not focus on consistency. Validity refers to how well an assessment measures what it is intended to measure. Normative typically relates to the interpretation of test scores based on a comparison with groups of test-takers, while authenticity addresses how well the assessment reflects real-world tasks and the relevance of the test content to actual functioning. Reliability, therefore, is specifically concerned with the consistency of the results yielded by an assessment.