Validation of Westside Test Anxiety Scale
The Westside Scale is found to be a valid measure, based on solid correlations between anxiety-reduction as measured by the scale and improvements in test performance. Westside scores and test scores were attained prior to and then again after half the sample experienced a high impact therapeutic Intervention . Anxiety reduction correlated to test gains r = 44, on average, indicating that changes in the Westside scale could account for 20% of changes in the objective tests. See Scale Validation
Note here that we are correlating anxiety changes with test score changes, which produces a more informative (more valid) result than merely correlating a new scale with results from existing scales. An anxiety reduction score which contributes to objective test gains is probably measuring something of more interest than one that does not contribute to test gains. Our intervention produced strong anxiety reduction and test gains, thus contributing to the high validation coefficient (cf nursing students).
Variations come with the territory. An intervention that produces strong anxiety reduction (clearly separating intervention vs. controls groups) will produce a higher validity result, whereas a weaker intervention will show a smaller result. And similarly with reliability measures. Students spread across the spectrum from extreme anxiety to no anxiety will show stronger test-retest scores, than will students who are all highly anxious (and differ mainly in some small error components between them.