Final answer:
Poor sampling of question material, lack of equivalence between tests, inconsistent testing conditions, and lack of internal consistency can all contribute to the unreliability of a test, but failure to predict job performance does not.
Step-by-step explanation:
The unreliability of a test may be explained by all of the following except:
A) poor sampling of question material
B) lack of equivalence between tests
C) inconsistent testing conditions
D) failure to predict job performance
E) lack of internal consistency
Out of these options, the one that does not explain the unreliability of a test is D) failure to predict job performance. Job performance prediction is a separate issue from the reliability of a test. The other options are all potential factors that can contribute to test unreliability.The unreliability of a test may be explained by all of the following EXCEPT failure to predict job performance. Options such as poor sampling of question material, lack of equivalence between tests, inconsistent testing conditions, and lack of internal consistency directly affect a test's reliability, which is the consistency of a measure. However, a test's ability to predict job performance is more about validity, specifically criterion-related validity, rather than reliability. Validity is concerned with whether the test measures what it's supposed to measure, while reliability is about whether it measures consistently.