Conceptual Graphs: An Overview, Software and Issues

Conceptual graphs are similar to entity-relationship diagrams. They are however a visual, advanced knowledge-based representation formalism based upon much richer philosophical, psychological, linguistic, and object-oriented principles. Although there is much interesting and ongoing work in the conceptual graphs arena, there is little of an introductory nature for newcomers to conceptual graphs. Given the beauty of conceptual graphs is that their diagrammatic presentation hides much of the complexity associated with traditional symbolic logic without any loss of its expressiveness, this paper therefore presents a short, up-to-date and straightforward overview of conceptual graphs for the diagrams community in general. It also introduces software to assist in this understanding. The paper identifies some studies revealing that conceptual graphs, though expressive, are based upon precise or ‘crisp’ as opposed to the ‘vague’ or fuzzy logic of the real world. (Indeed conceptual graphs diagrammatically highlight this by hiding traditional logical complexity.) By presenting conceptual graphs in a way that is understandable by the diagrams community, the paper alerts us all to the strengths, and limitations, in diagramming the real world in this way. The paper therefore offers some pertinent suggestions as to future work in this and related areas.