The growing international interest in the field of reusable learning objects suggests that the learning objects' approach is an innovative one, leveraging the development and deployment of e-Learning content in new and interesting ways. Although there are numerous development projects based on the learning objects' approach, there are few studies that have provided guidelines for determining return on investment on learning objects. We believe that without such studies it is difficult to determine the usability and effectiveness of learning objects, and so the current huge amount of development effort will not scale. To deal with this shortcoming, we propose a new model for evaluating learning objects. In this model, four major aspects of learning objects are evaluated: content design, back-end delivery, front-end presentation, and the learning process itself. We argue that these aspects are closely linked, and show how each one of them plays an important role in the development life cycle of a learning object.