美國Advanced Distributed Learning（ADL）提出了Sharable Content Object Reference Model（SCORM）標準，來規範學習元件之結構與執行。透過SCORM標準不但使得學習元件可以輕易的分享、重複利用，達到節省時間與成本的優點。之後更提出了Content Object Repository Discovery and Resolution Architecture（CORDRA），一個具有高度互通性儲存體，達到發現、分享與重複使用學習元件之目的。然而SCORM與CORDRA雖然可以使得學習元件再利用，但是卻無法顯示學習元件再利用之後與本體的關聯性，一旦當使用者面對龐大數量且極度雷同的課程之際，如何比較、選擇合適的學習元件將是一大考驗。本篇論文將介紹一結構化的學習元件關係－Reusability Tree以及遵循CORDRA架構所建置的學習元件儲存體－MINE Registry。透過強化MINE Registry系統以及Reusability Tree的應用將可以提供使用者學習元件之間的關聯性，並提出其相似性與差異性計算公式，使用者進行搜尋之際除了更為便利之外，還可獲得額外的隱含資訊來協助教學設計。除此之外更進一步強化與課程編輯系統、學習管理系統的互動，設計學習元件參照次數計畫方式以及排名方法，使系統間之互動與整合更為緊密，達到儲存體的每一筆資料均能進行全面性之比較，加強儲存體提供之服務與效用。 The SCORM (Sharable Content Object Reference Model) standard defines metadata of learning objects, which are used as the elementary reusable components in distance learning. The CORDRA (Content Object Repository Discovery and Registration/Resolution Architecture) standard provides a common architecture for the resolution, discovery, and sharing of these learning objects. They define standardized ways in which learning objects can be discovered and reused by content designers. However, the current CORDRA and the definition of objects in SCORM only allow an object to be copied, updated, and re-organized in a new content aggregation, which is used as a delivery package to end users. This paper proposes a revised CORDRA architecture and a reusability mechanism to make instruction design easier. We propose a structure called a Reusability Tree for tracking the history of reuse of learning objects in CORDRA. This thesis also defines the notions of similarity and diversity of learning objects to make easier for users to precisely search for reusable learning objects, with additional meaningful information to support instruction designs.
