Abstract: An evaluation method for service quality based on customers’ linguistic assessment information was proposed to solve the problem of service quality evaluation for multiple service programs or projects of the same type. Firstly， customers’ linguistic assessment information of service programs was obtained by questionnaires and transformed into trapezoidal fuzzy numbers. Then， the average weight of each index， the average perceived performance of service programs with regard to each index and the average service expectation of all the customers for each index were calculated. Furthermore， the service quality evaluation value of each program was calculated by using fuzzy weighted averaging operators， and the similar degree between the service quality evaluation value and the trapezoidal fuzzy number corresponding to each linguistic term was calculated whereby the service quality level for each service program can be determined. For programs at the same level of service quality， their advantages and disadvantages were compared by calculating nonfuzzy values. Finally， a numerical example was given to illustrate the validity and practicality of the proposed method.

Key words: service quality evaluation, linguistic evaluation information, trapezoidal fuzzy number, fuzzy weighted averaging operator, similar degree