In spite of all the attention that the concept of learning objects has received in the education community, it remains poorly defined. This paper attempts to explore what may be a learning object other than some computer file catalogued in a digital library for reuse. Any debate about what a learning object may be is premature without a general understanding of the learning activities in which it is to be used. There is the possibility for a learning object to be conceptualized as an interactive visual representation which can be used as a mediating tool in a learning activity. The use of learning objects potentially leaves a cognitive residue in the form of an internal psychological tool which might add to the overall intellectual capacity of the learner. This paper opens a number of important issues for further research into the design and utility of learning objects as interactive visual representations and mediating tools in learning activities.