Expectation-based quality of service assessment

The ability to gauge quality of service is critical if we are to realise the potential of the service-oriented computing paradigm. Many techniques have been proposed for calculating the quality of a service, and they do so typically by collecting quality ratings from the users of the service, then combining them in one way or another to derive the quality of the service. We argue that collecting quality ratings alone from the users is not sufficient for deriving a reliable and accurate quality measure for a service. This is because different users often have different expectations on the quality of a service and their ratings tend to be closely related to these expectations, i.e. how their expectations are met. In this paper, we propose a quality of service assessment model based on user expectations. That is, we collect expectations as well as ratings from the users of a service, then calculate the quality of the service using only the ratings that have similar expectations. Our experiments show that the method we propose here can result in more meaningful and reliable quality ratings for services