A FORMAL MODEL FOR LEARNING OBJECTS

Formal models are useful both to describe existing objects and concepts and to prescribe how they should be. This paper describes FLOD, a formal model for characterizing learning objects. FLOD details on one hand those components required for a digital resource to be considered a learning object and on the other hand states the type of interactions that should exist between the actors involved in the development process of learning objects. FLOD is divided then into a composition model and a group model. The Composition model is based on layers that formally describe the elements that make up a learning object and the way these elements must be assembled in order to be significant objects (objects with meaning). The group model identifies the main roles and activities involved in the process of generating learning objects through an organizational structure diagram, a task diagram, and a collaboration diagram. Finally, the formalization of both the composition model and the group model is stated using the Z language. Such formal specification made possible a notation where specifications are written, a universe of objects that can be specified and a set of relationships that indicates which objects correctly fulfill the specification. To guarantee the correction of the specification made, the implementation of a system based on such specification is initiated, and a system with well-defined syntax and semantics is obtained. The conclusion is that the formal model as proposed allows the definition of a notation that precisely describes the learning objects on both component and interaction levels.