本研究旨在探討專題式小組網路溝通互動之機制，希望藉此研究瞭解小組成員的溝通互動情形與學習成效之間的關係。研究源起於愈來愈多的網路工具被發展應用於教育的領域，教育者欲籍由資訊科技的使用輔助學生進行合作學習，並促進網路學習的成效，然而小組合作學習的績效會受到成員互動的影響，而目前針對網路學習小組進行長時間互動歷程研究的文章並不多，缺少教學者欲研究方面的具體參考資訊。因此，本研究嘗試進行初探性的研究，採個案研究法，選擇一個實施網路專題式學習的大學課堂為研究場域，針對其中表現特優的小組進行溝通互動機制之個案研究，並採用質化的內容分析法進行資料分析。研究結果發現，小組成員在每一個專題階段皆會表現出程序性、任務性及社會性的溝通互動行為：但是在不同專題階段，小組成員會隨時間及任務型態的不同，而傾向發展不同類型的溝通互動行為。專題的準備階段及完成階段皆以任務性溝通互動為最多，而在專題執行階段則以程序性的溝通互動最多。研究最後提出一個網路專題式學習小組專題歷程與互動行為表現概念模式，希望藉此提供未來學校教學實施應用及研究的重要參考依據。

With the development of information technology, applications of web tools in education have become wider and wider. Although researchers have been putting efforts in developing web tools in support of students collaborative learning, however, the performance of team collaborative learning is impacted by member's interaction. This study adopts the case study approach to explore group interaction behaviors with the application of internet tool in doing the project-based learning to understand their communication process and learning performance. This study was carried out in a web-based college course with project-based learning implementation. The most successful team was chosen as the target case to study their group process and communication interaction. The results show that team members in every stage performed procedural, task-oriented, and relationship-oriented communication interaction behaviors. However, in different stage, different behaviors are developed along with changes of time and tasks. There are many task-oriented interactions happened in both preparation and completion stage, and lots of procedural interactions in implementation stage. This study further propose an effective interaction model about web-based project-based learning team, and hopes to provide a research base practical application references for prospective use.