National Evaluation Series (NES) Assessment of Professional Knowledge Practice Test

What does it mean if a test has a high standard deviation?

1. There is high variability among the scores

2. There is low variability among the scores

3. Students scored exceptionally high

4. Scores cluster toward the middle

The correct answer is: There is high variability among the scores

A high standard deviation in a set of test scores indicates that there is significant variability among the scores. This means that the scores are spread out over a wider range, with some students scoring much higher or lower than the average. In the context of test results, when the standard deviation is high, it suggests that the performance of students varies greatly; some may perform very well while others may struggle. This variability can reflect differences in understanding, ability, preparation, or even the test's difficulty level. In contrast, a low standard deviation would suggest that the scores are clustered closely around the mean, indicating that most students performed similarly. The other choices relate to specific interpretations of scores that do not necessarily connect to the concept of standard deviation directly; for instance, scoring exceptionally high or clustering toward the middle implies a different distribution of scores that would typically correspond to a low standard deviation.