The representational nature of maps, however, is often ignored – what we see when looking at a map is not the word, but an abstract representation th… - Alan MacEachren

Without categorization, maps would not be possible.

To make maps that work, we must depict categories using methods that match the structures of human mental categorization.

Jacques Bertin's books Semiology of Graphics and Graphics and Graphic Information Processing have been stimuli for my own thinking about the representation and analysis of geographic information. I have also used both books as core readings for graduate seminars and they have generated lively discussion and prompted innovative research. I often ask graduate students to consider how cartographic research and practice in the U.S. might be different today if the English edition of Semiology of Graphics had appeared in 1967 (when it was published in French), rather than in 1983. I know that my own work would have been dramatically different if I had encountered these ideas a decade and a half sooner.