The first category of problems is that of recognising representations of single objects. This depends on the ability to connect the abstract lines and shapes on a piece of paper with the real concrete world. Seth Spaulding writing in Audio Visual Communication Review, Winter 1955, Vol. 3, No. 1, in an article entitled Research on Pictorial Illustration maintains that “an illustration is an abstraction, and for the viewer meaning exists only to the extent to which the observer has experience with which to interpret the drawing and to the extent to which the observer can relate the lines on the paper to the actual experience which it represents”.