A FORMAL MODEL FOR LEARNING OBJECTS
This paper presents a formal model for the characterization of Learning Objects (LOs). The model describes what are the necessary components for a digital resource to be considered a LO and defines the type of interaction that must exist between the actors involved in the development of the LOs. The model is divided then in a composition model and a group model. The composition model is based on content by layers to formally outline the elements that constitute the LOs and how to assemble them in order to obtain more meaningful elements. The group model identifies the main roles and activities involved during the generation of LOs through a diagram for the organizational structure, a diagram of tasks and a diagram of collaboration. Finally is presented the formalization of the composition model and the group model, the Z language was used for this formalization. With this formal specification were obtained a notation in which the specifications are written, a universe of objects that can be specified and a set of relations that indicates which objects satisfy correctly the specification. In order to guarantee the correction of the specification, a system based on this specification was implemented. The system obtained has defined correctly the syntax and semantic. We conclude that the proposed formal model allows us to define a notation that describes in a precise way to the learning objects in their components and interactions.