Examining the measurement and structural invariance of LibQUAL+® across user groups

The LibQUAL+® instrument measures users' perceptions of library service quality; three factors are evaluated: Affect of Service, Information Control, and Library as Place. Although previous studies have assessed the factorial invariance of LibQUAL+®, factorial invariance by itself is insufficient for score comparability across groups. Stronger levels of measurement invariance need to be established. This study systematically tested the measurement and structural invariance of LibQUAL+® scores in a sample of 1551 undergraduate students, 707 graduate students, and 134 faculty members. Multi-group confirmatory factor analyses showed that full measurement invariance did hold between students and faculty for the complete instrument. Building on the measurement invariance, structural invariance models showed that factor variances were equivalent across user groups, but factor covariances and means differed. Faculty had higher perceptions of Affect of Service and undergraduate students had higher perceptions of Library as Place compared to the other groups.

► Measurement invariance of LibQUAL+® was systematically tested across 3 user groups.
► Full measurement invariance held across undergraduates, graduates, and faculty.
► After establishing measurement invariance, structural invariance was investigated.
► Factor variances were equal across groups, but covariances and means differed.