This paper revisits a conjecture - originally stated by Parasuraman, Berry and Zeithaml (PBZ) - according to which the greater the perceived importance of a service quality attribute, the thinner should be the corresponding tolerance zone. The paper tests the intuitive idea that importance is directly associated to the minimum acceptable level of service. Data originated from a study of postal services in Brazil and were collected through a postal, three-column SERVQUAL-type questionnaire returned by 540 Brazilian companies. Results suggest that minimum service is a better measure of importance in comparison to the tolerance width and imply that researchers may limit their search for important attributes to computing and ordering the corresponding minimum level of service.
service quality; attribute importance; service quality evaluation; marketing research
