Validity versus reliability

Abstract

After reviewing recent studies involving the selection of items for interest scales, in which scales with higher validity (and fewer items) generally had lower reliability, the author presents the original odd-even reliabilities and recently-collected test-retest reliabilities (over an average 18-year interval) for 15 scales of the Strong VIB. The test-retest reliabilities were all lower than the odd-even reliabilities, and the shrinkage was greatest for those scales with the lowest original reliabilities. It is concluded that, for prediction in the distant future, scale reliability is important. (PsycInfo Database Record (c) 2025 APA, all rights reserved)