A complementary analysis of the perception gap is the RATER model also produced by Zeithaml (1990). RATER identifies the 5 key areas which together form the qualities of a service offering from a customer perspective. Where the Gap model describes the how the provider can minimise the perception gap RATER focuses on the dimensions of customers expectations. The research also suggests the relative importance of each of the factors.
The RATER factors help provide specific dimensions which can be used to analyse and measure customer expectations. These will be further discussed when reviewing measurement techniques below. The RATER factors are synthesised from an earlier 10 factor analysis.