A Usability Evaluation Model Based On The Degree Of Usability For Web Service

With the rapid development of internet technology, various applications which based on the Web service become the focus of public's attention with its characteristics of convenience, high speed and easy to operation. All of these characteristics promote traditional business, education, finance and other industries undergoing profound changes in service delivery and there appear an increasing number of service provider and more extensive web service. However, since Web service always operate in a complicated network circumstance, which is also dynamic and open. There are many platforms for implementation, and the users are quiet distinctive from each other. Thus, it is the uniqueness and complexity of the Web service makes us have difficulties in assessing the availability and assuring quality. The existing theories and methodologies for usability testing of web service, such as Object-oriented Web Test Theconology and Two-story model of Web application testiong technology, though they came up with some methods to test the accessibility of Web service from different aspects, we cannot make it because of high complexity. Further more, there are no uniform evaluate system and index composition for all kinds of testing methods. Thus, problems like testing is not standardized and defining the quality standards are existing. It is a challengeable research subject that how to choose the best accessible service from similar Web service and insure its quality and effectiveness.This thesis based on the analysis of construction of classical Web service system, proposed the concept of Web Service Availability, designed a Web-based service availability measurement model. From the perspective of service requestors, it can choose the appropriate service quality index such as response time, availability, price, security level, throughput and data delay, depending on different requirements. It also can quantify the availability of these indicators. It considered availability as a reference to evaluate usability test of a Web service. If we need to evaluate the accessibility of some Web service, several steps should be taken. First, collect the target data of available service. Then, transform these original data from linear range into the same value range. Last, make quantitative analysis of availability in the light of evaluation parameters in order to provide the basis of accessibility evaluation and service choices. Finally, combining with Internet, this thesis takes several Web service for examples. It collects original indicator data based on availability. Then, it can get the ranking orders of availability from using some procedures such as standardization to evaluate quality indexes. As a result, it can provide service requesters some references to choose the best service. The consequence indicates that the model have universality and referential value.