Case-Based Advice System for Novice Programs Written in Assembly Language

我们制定了一种方法，使用基于案例的推理方法在编程教育中为新手程序提供建议。我们建议的目标项目被称为“侥幸项目”。near-miss程序是指不能正常运行但与正确程序相当接近的程序。我们提出了一个循序渐进的建议模式。也就是说，建议系统首先给出小提示，然后根据需要给出更多提示或详细建议。学生用小提示解决问题比用详细的建议解决问题更有信心。我们还提出了两种基于案例的建议句生成方法。第一种方法是基于建议案例的相似性生成建议句，其中包括一个未遂程序作为问题描述，以及关于该程序的建议句作为解决方案描述。第二种方法是基于目标脱靶程序和正确程序之间的差异生成建议。我们已经实施的评价辅助系统的评价案例库中有很多正确的程序。基于这些思想，我们为简单的汇编语言CASL II实现了一个基于案例的通知系统。该系统已在实际课堂中使用，结果表明基于案例的咨询系统是有用的。特别是，我们发现基于差异的方法非常有用。即使最初的案例库是空的，基于差异的方法也会提出建议句，因为基于差异的方法使用的是教师在评估学生提交的课程时自动添加到案例库中的评估案例。

We worked out a method of giving advice for novice programs using a case-based reasoning approach in programming education. Our target programs for the advice are called near-miss programs. A near-miss program is a program that does not run properly but is rather close to correct programs.We proposed a model of giving step-by-step advice. That is, the advice system gives small hints at first and then gives more hints or detailed advice later as needed. Students will gain more confidence when they solve problems with small hints than in cases where they got detailed advice.We also proposed two case-based methods of generating advice sentences. The first method is to generate advice sentences based on the similarity to advice cases, which include a near-miss program as a problem description and advice sentences on the program as a solution description. The second method is advice generation based on the difference between the target near-miss program and a correct program. There are many correct programs in evaluation case-bases of the evaluation assistant system we already implemented.Based on these ideas, we implemented a case-based advice system for a simple assembly language CASL II. The system had been utilized in actual classes and the results suggested that the case-based advice system was useful. In particular, we found that the difference-based method was very useful. Advice sentences were presented by the difference-based method even if case-bases were empty at first, because the difference-based method uses evaluation cases which are added to the case-base automatically when teachers evaluate students' submitted programs.