A few years ago I ran across the following quote in the magizine Newsweek that illustrates some of the great power in finding the right metaphor. ``Unlike the usual programming method -- writing software one line at a time, NeXT's object-oriented system offers larger building blocks that developers can quickly assemble the way a kid builds faces on Mr. Potato Head.''
The metaphor is effective, since it immediately conjures up images of assemblying components to create a new entity, and the large number of ways in which a few simple components can be assembled to construct a wide variety of different results. Thus, our experience from real life can help us understand this new idea.