I hope that this paper has shown that the key issue facing multimedia technology implementers is not primarily a technical one (although technical performance is important) but a design one. We need to know where and when particular media combinations will enable us to achieve our goals more effectively. Because the advantages (or disadvantages) of multimedia usage depend upon the tasks being performed, it is difficult to set up precise laboratory studies and apply the results directly to real life situations. The answer here is probably more longitudinal studies in real situations. However, we are now reasonably confident that our list of guidelines will eventually extend into a methodology.
There are issues that have not been addressed in this paper. For example, dynamic allocation of multimedia resources raises major issues about interface consistency. We believe that, provided the representations change only occasionally and only in critical resource situations, this need not be a serious problem. However, this is a matter for debate.