本研究旨在歸納電腦輔助國中英語任務教學之設計原則，並探究學生在使用電腦軟體時的互動模式。同時，本研究期望能進一步了解，針對此一教師設計之電腦輔助英語教學軟體，學生在使用過程所遇到的困難及與學習夥伴互動的模式。 本研究採取質的研究方法，並且以設計本位研究的概念為架構。研究者先行設計出一套任務導向之電腦英語教學軟體，作為研究雛型。研究對象為九對高學習成就之國中生。研究時程分為三個階段，每個階段由三對學生者參與。藉由觀察及訪談，分析出學生(1)分別在三個階段所遇到的困難，以及(2)與夥伴互動的模式。在第一部份，先一一探討學生對於每個任務的反應，再歸納出重要的教學議題及軟體在下一階段所應作的修正。在第二部份，先討論學生在互動的過程所扮演的角色，再呈現訪談資料裡學生內心對於互動過程的感受。本研究發現，符合學生學習需求的軟體設計、教師所提供的心理支持、及學生互動的品質，皆是影響電腦英語教學成效之關鍵因素。 本研究根據以上軟體設計及學生互動的討論結果，進一步提供建議，以作為任務導向之電腦英語教學相關議題之研究參考。 / The purpose of this study is to derive useful insights and principles for the design of the computer-supported collaboration tasks and to explore patterns of learners’ interaction when working on the computer tasks. This study attempts to understand how learners react to the teacher-designed computer-supported collaborative learning tasks and how they work together with their partners. This study adopts qualitative approach methods within the design-based research framework. First, a task-based computer program is designed as a prototype. Then 9 pairs of high-achieving junior high school students are selected to use the software. Throughout the three cycles of implementation with three pairs of students in each, qualitative data are collected through direct observations and an interview. The results are presented according to the three cycles with a separate section on the participants’ interaction. In the three cycles, the participants’ reactions to each task within each scene are first described, and then pedagogical issues and design adjustments for the next cycle are discussed. In the interaction section, three roles taken by the participants across three cycles are identified, with a discussion on the participants’ viewpoints on their interaction. It is found in this study that the program design, the teacher’s support, and the nature of the learner’s interaction are the key elements affecting the outcomes of using this CSCL program. Finally, pedagogical implications and suggestions based on obstacles that the participants encountered during the program are discussed, with the discussion on limitations of this study and suggestions for further research.