Buttle (1996), in his critical evaluation of SERVQUAL, identified several theoretical shortcomings. Among these deficiencies are the process orientation and the dimensionality of SERVQUAL. Several researchers have argued that SERVQUAL measures only the service process dimensions (i.e. interaction quality) but not the perceived quality of the service outcome. If true, the instrument does not measure, for instance, the quality of a haircut (service outcome). Further, Buttle (1996) questions the adequacy of the overall model and suggests that the dimensionality is context specific (i.e. dimension importance depends on service type). To this end, Babakus and Boller (1992) state that service quality may be complex and multi-dimensional for some services and unidimensional for others. A similar finding was made by Llosa et al. (1998) who state that the nature of the service quality dimensions vary by service and, therefore, the authors even question if one can go beyond the two factor model suggested by the European school of thought. Mels et al. (1997) also found more support for the broader two-factor European model.