1996．第11卷第1期（Vol. 11 No. 1）．pp. 2431
Logex An Intelligent Computer Tutor in Logarithms
The use of computer in education started more than thirty years ago. In traditional computer assisted instruction systems, all responses have to be preplanned and implemented at the designing stage. The system builders must prespecify all available routes through the space of teaching possibilities. Every test, every decision, every branch leading to some remedial material and every exposition must be written in advance (Goodyear, 1991). When considering the number of decision points with their corresponding responses, the possible number of combinations, even for small tutoring systems, will be enormous. This prevents computer assisted systems from being used in larger subject area. Recently, with the aid of knowledge representation techniques originating from artificial intelligence, human knowledge can be incorporated into computer systems. Based on the knowledge incorporated, computer systems can now make judgments on students' responses and decide on suitable responses to be made in real time. There is no need to pre-install all the possible routes and decision points. The computer system is thus smaller in a sense that less memory space is required on the hardware. Besides, the responses generated in real time can be more flexible and more adapted to students' needs. Logex is an example of such systems, called intelligent tutoring systems, which are designed to help students in simplifying logarithmic expressions by working through the simplification process with the students. This article describes its principles, structure and the ways by which it helps students.
電腦應用於教育上已有三十年的歷史。早期電腦輔助教學系統的設計，由於每一問題、學生的可能反應、與及隨後的輔助辦法等，都需要預先估計，然後設置於系統內。這種辦法，除了比較繁瑣外，亦需要較大的電腦記憶空間來貯藏這許多資料。所以對於那些需要廣闊學科知識的範疇來說，要使用這種方法來設計電腦輔助教學系統，存在著不少的困難。近年來，由於人工智慧的發展，已能將人類的知識析出，將之設置於電腦系統內。基於此內置的知識，電腦系統可以就學生的反應，即時判斷其對錯，然後提出適當的補救辦法。由於此種系統比較接近真人教師輔導學生辦法的關係，所以被稱為智慧型電腦輔助教學系統（intelligent tutoring syslem）。智慧型電腦系統由於不需要預置所有可能反應及輔導辦法，需要的電腦記憶空間比較少，相應地可以處理的知識範圍亦比較廣闊。本文即介紹一個這樣的智慧型電腦輔助教學系統Logex，其設計內容及幫助學生辦法。