So which score on the LibQual+™ tells me if library users are satisfied?

Scores on the LibQual+™, a standardized measure of academic library service quality grounded in Expectation Confirmation-Disconfirmation theory, were analyzed to determine whether the perceived score, a direct rating of service quality, is a more valid indicator of user satisfaction than the superiority gap score, which is the simple difference between the perceived performance rating assigned to the service and a desired level of performance. According to the theory underlying the LibQual+™, the score with the highest correlations to eight validity indicators should have been the superiority gap score, but this study found that the perceived score is a better predictor of satisfaction than the superiority gap score. Once the perceived rating is partialled-out from the correlation between the superiority gap score and the validity criterion, the value of the gap score becomes almost nil. The data call into question the use of the superiority gap score to infer satisfaction.