Identifying shortcomings in the measurement of service quality

Abstract

SERVPERF, the performance component of the Service Quality scale (SERVQUAL), has been shown to measure five underlying dimensions corresponding to Tangibles, Reliability, Responsiveness, Assurance, and Empathy (Parasuraman, Zeithaml, & Berry, 1988). This paper describes a validation study, employing four different datasets, of a shortened 15-item version of the SERVPERF scale to be called SERVPERF-M. Exploratory and confirmatory factor analytic techniques were used to explore the dimensionality of the scale. Although internal consistency estimates for all scales were very satisfactory for all four datasets, the factor structure was somewhat unstable with Responsiveness, Assurance and Empathy tending to define a single factor in three of the sets and Reliability and Tangibles to define two other factors. Rasch analysis was employed to gain further insights into the behaviour of the items. These analyses suggested that the five factors can be treated as five different stages of service quality, rather than as five qualitatively different dimensions. The Rasch analysis also suggested that the items in both SERVPERF and SERVPERF-M are too easy to rate highly and that more 'difficult' items need to be added to the scale. If this is done, it is likely that some of the confusion that exists over the dimensionality of this scale will disappear.