(with high contact ticket counters and low contact baggage handling), pure service characteristics within the planes, and quasi manufacturing (moderate contact) characteristics in their billing and airline maintenance operations. According to this classification, the required skills of the work force in high- contact systems are characterised by a significant public relations component. Thus, any interaction with the customer makes the direct worker in fact part of the product and therefore his attitude can affect the customer's view of the service provided. Finally, although Chase made a useful distinction, it is not as helpful as it could be. A number of services can be considered high contact even though they only "shelter the customer" and in the process have very little interaction with the client. To use Chase's example, a hotel is a high-contact service, but to others, hotels are vastly less demanding than are hospitals, primarily because hotels interact with customers in limited and very structured ways, whereas hospitals must interact with patients in irregular and frequently sustained ways. Also, these classification schemes become more problematic when Chase turns to examining potential operating efficiency: Chase adds that potential facility efficiency = 1- ct ; where ct = customer contact time, and st = service creation St time, thus the greater the ratio of customer contact time, the lower the potential efficiency of the service facility. Therefore, the notion of client contact may be fraught with more ambiguity than is necessary (Schmenner 1986).