Abstract: The traditional QoS-aware Web services selection methods need accurate weights given by the users to  empress their preferences over different QoS properties. A QoS-aware Web service group evaluation method is proposed to solve the problem of service selection of the users whose preferences are indeterminate. This paper analyses the necessity of Web services group evaluation in detail. Then it gathers the historical selection results of the users who have explicit preferences to obtain the group evaluation of Web services by Condorcet and Borda function of group decision-making theory. Thus, user who has no specific QoS preference can select services referring to the evaluation result. The theoretical analysis and simulation experiment validate rationality and availability of the Web services evaluation method.

Key words: Web service, Quality of Service（QoS）, service community, service evaluation, decision-making method, social choice function

摘要： 传统QoS感知的Web服务选择方法需要用户给出精确权重以表达其对QoS属性的偏好。为解决用户无明确偏好情况下的服务选择问题，提出了一种QoS感知的Web服务群体评价方法。对Web服务群体评价的需求进行了详细的分析，以有明确QoS偏好的用户对服务的历史选择结果为基础，利用群决策的Condorcet和Borda函数集结这些结果得到服务的群体评价，从而使得无明确QoS偏好用户可以参考该评价结果进行服务选择。理论分析和仿真实验验证了该服务群体评价方法的合理性和有效性。

关键词: Web服务, 服务质量, 服务社区, 服务评价, 群决策方法, 社会选择函数