Abstract: The knowledge representation is a key aspect in the computer Intelligent Tutor System(ITS), which determines the effect of the inference process. Moreover, it is necessity of the combination of the knowledge base with the teaching material base in ITS because it contains a lot of multimedia data. In this paper, a discussion of construction of the knowledge base by the relational model(RM) is presented. We analyze the knowledge into groups, each one called a knowledge point. Then, use RM to organize the knowledge points to form two databases；one is called the attribute database, and the other called linkage database. The attribute database gives each knowledge point attributes and a link to the teaching material base, while the linkage database describes the relation among knowledge points. This linkage database is suitable for ratiocination. In order to build the systematic teaching courses, we construct a strategy database. As an example, we discuss the knowledge representation of the cone section in the mechanical drawing class.

Key words: knowledge representation, relational model, intelligent tutor system, ITS

摘要： 在计算机智能导师系统(ITS)中，知识表示是一个关键问题。它是计算机智能教学的基础，其结构决定了智能推理过程的有效性。同时教学系统还必需具有大量多媒体数据的管理能力，学科知识库与教学材料库结合也是一个重要问题。本文使用关系模型讨论建立学科知识库的方法。首先把学科知识分解为知识点，用关系模型来组织知识点，形成知识点属性库和链接库。知识点属性库描述知识点的特性和与多媒体教学材料库的连接关系；知识点链接库反映知识点间的关系，便于推理。为了形成系统的教学过程，还必需建立教学策略库，以规定教学策略模板和规则。本文使用机械制图课程中的圆锥体一节作为例子，展开讨论。

关键词: 知识表示, 关系模式, 智能导师系统, ITS