本研究目的是建置國小數學速率單元問答自動回覆系統，學生可提出有關速率單元學習問題的關鍵詞，經由系統自動回覆，幫助學生解決學習問題，獲得即時準確的解答。主要貢獻如下：一、依據蓋聶 (Robert Mills Gagné) 教學理論中，從學生學習能力發展出「學習階層」（Learning Hierarchy），並開發速率單元的學習階層和問答自動回覆系統的問題文件、關鍵詞與問題解答。二、利用關鍵詞權重法與餘弦向量相似度方法，找出與使用者所輸入之關鍵詞最相近的問題文件；並使用ASP.NET、Access、與Flash 工具，開發網際網路版之國小數學速率單元自動問答回覆系統。三、本系統包含「問題關鍵詞輸入機制」、「相似問題文件自動回覆機制」、「問題解答回覆機制」三個模組，利用電腦之瀏覽器即可接受學生提出問題關鍵詞，並自動回覆解答。為進行本系統的實施與評估工作，立意取樣三所小學六年級學生實際測詴本系統，並以自編問卷了解學生使用系統的滿意度，大多數接受測詴的學生表示：確實可即時獲得系統自動回覆解答，能有效解決速率單元的學習疑問，並提升學生學習興趣。

An auto-reply system of questions and answers on mathematic speed unit has been developed for elementary school students. This system can immediately provide accurate answers as students request questions on the speed unit. The major contributions are described as follows. The documents, keywords, and answers are built for the auto-reply system of questions and answers, according to Gagné theory of the learning hierarchy. The term-weighting approach and the cosine similarity measure method are utilized to find the documents that are similar to the keywords that users key in. The ASP.NET, Access, and Flash are used to develop the auto-reply system. It includes mainly three modules, which are keywords input mechanism, auto-reply mechanism of similar documents, and answer mechanism for questions. The sixth grade students in the three elementary schools by purposeful sampling are chosen to test the system performance. After implementation, they fill out the questionnaire designed by researchers. Most students agree that the auto-reply system can effectively solve the questions of the speed unit and improve students' interest in learning.