Factorial invariance of LibQUAL+® as a measure of library service quality over time Original Research Article

LibQUAL+® is an instrument purported to measure three dimensions of library service quality: service affect, library as a place, and information control. After changes were made to the instrument in 2003, however, no confirmatory factor analyses have been published in peer-reviewed journals affirming the three-factor structure of LibQUAL+®. These deficiencies were addressed by testing the hypothesized three-factor structure and the stability of that structure over time. Specifically, data from three samples (n = 550; n = 3261; n = 2103) were collected over a five-year period and analyzed using a multi-group confirmatory factor analysis. Results suggest that the theoretical model fit the data across the three samples and demonstrates factorial invariance over time. Multicollinearity between affect of service and information control, however, indicate that service quality may be measured as two dimensions rather than three, providing a more parsimonious explanation of service quality.