A current popular paradigm in e-learning is that of the "learning object". Broadly de-fined, a learning object is a reusable piece of educational material intended to be strung together with other learning objects to form larger educational units such as activities, lessons, or whole courses. This aggregating of learning objects together is a recursive process – small objects can be combined to form medium sized objects, medium sized objects can be combined to form large objects, and so on. Once objects have been com-bined appropriately, they are generally serialized into content packages, and deployed into an online course for delivery to learners.Learning objects are often stored in distributed and decentralized repositories throughout the Internet. This provides unique challenges when managing the history of such an ob-ject, as traditional versioning techniques (e.g. CVS, RCS, etc.) rely on centralized man-agement. These challenges have been largely ignored by the educational technology community, but are becoming more important as sharing of learning objects increases.This thesis explores these issues by providing a formal version model for learning ob-jects, a set of data bindings for this model, and a prototype authoring environment which implements these bindings. In addition, the work explores the potential benefits of ver-sion control by implementing a visualization of a learning object revision tree. This visualization includes the relationship between objects and their aggregates, the struc-tural history of an object, and the semantic changes that an object has undergone
