If a test demonstrates high reliability, which of the following is likely true?

• A. The observed scores are consistent across administrations
• B. The standard error of measurement is large
• C. The test has poor validity
• D. The test length does not matter

Answer: (A)

Reliability is about consistency. When a test is highly reliable, the scores you get are stable across repeated measurements, meaning a person would tend to get similar results if they took the test again or on different occasions.

Because reliability is high, measurement error is small. That shows up as a small standard error of measurement, so observed scores don’t wander much due to random error.

So the statement that best fits high reliability is that observed scores are consistent across administrations. The other ideas don’t align with high reliability: a large standard error of measurement would imply more randomness and less reliability; validity is a separate property (a test can be reliable but not valid for a specific purpose); and test length can influence reliability in practice, since longer tests often yield more stable estimates, so saying length doesn’t matter isn’t accurate.