隨著網路視訊科技的持續發展，使網路教學的互動可以藉由視訊討論工具，達到老師與學習者在網路上同步教學，並透過影音視訊及檔案文件分享進行即時面對面教學，讓學習者在網路學習的過程中，能夠獲得即時的回饋。本研究主要目的在於探討數位學習視訊討論工具應具備的功能；並實施視訊討論工具之i-Share、JoinNet以及iChat AV三者之介面評鑑。研究對象為十八位淡江大學教育科技系學生，各別分為三組使用三項不同的視訊討論工具，並設計小組討論、專題報告及遊戲等三種網路教學策略為教學活動主題，進行使用者效能測試、訪談與滿意度調查，綜整所得資料，做為視訊討論工具功能發展與介面設計原則之依據。 Along with the continuous development of digital video technology, the synchronous interaction between the instructor and students in web-based instruction can be accomplished via video discussion tools. Therefore, the online face-to-face instruction is now available through video communication and document sharing. During the instruction, the students can receive feedbacks immediately. The purposes of this study are, first, to investigate the necessary function of video discussion tools; and secondly, to evaluate the user interface of three commonly used video discussion tools: i-Share, JoinNet, and iChatAV. The subjects are eighteen students of Tamkang University Department of Educational Technology. They were divided into three groups to engage in on-line video discussion activities designed with three different instructional strategies: group discussion, project presentation, and instructional game. Data were collected from user performance test, interview and satisfaction questionnaire. The results are used as the basis for the design and development of the user interface design for on-line video discussion tools.