To quantitatively analyze the reason of Web service failures and performance degradation,a model of the user perceived availability in cluster based Web servers is proposed.

The process of obtaining design knowledge and user knowledge was applied to capture knowledge of usability.

Based on the user s requests, the users are introduced into the whole process of product conceptual design and the process of user-designer interaction in the computer supported cooperative conceptual design and the expression of user knowledge are discussed in order to enhance the innovation affinity and comfortableness in the stage of product conceptual design.

Three kinds of problems about eliciting user knowledge are discovered through analyzing the test results and the hypothesis of method on eliciting user knowledge based on using products is set up.

First, this paper analyzes the characteristics of multimedia training system, and points out the problem in current multimedia system design interiorly, according to the experience and the idea of industry design, put forward a method of multimedia training design based on user cognition.

The user and document management and the communication mechanism implementing user awareness using multiple HTTP servers are emphasized.