Once I gave a talk to authors about textbook publishing. They wanted to know what I, as a publisher, was looking for from an author. I thought the best way to summarise that my views was to use a metaphor, so I proposed that authors should take as their model the work of Harry Beck.
Harry Beck was a draughtsman who, between the wars, worked for the London Underground in the signal engineers’ office. He decided to re-design the map of the underground to make it easier for passengers to find their way around. The map he designed (see http://britton.disted.camosun.bc.ca/beck_map.jpg) was based on the following principles:
1. Beck made no attempt to make the distances between stations on the map proportional to the distances in reality.
2. He simplified the angles at which lines intersected, basing his map on 45 and 90 degree angles.
3. He used a clear colour scheme to differentiate between lines.
Overall, the map was (to use the words of the Oxford Dictionary of National Biography) “topologically correct but topographically distorted”.
Beck’s approach seems to me to provide an excellent model for textbook authors. It is rooted in the needs of its users. It uses simplification to enhance navigability.
I have discussed this idea with many authors, both at my talk and since. I find some of them unhappy with it. It is the simplification that bothers them. They feel that writing a textbook the way that Beck designed his map would involve an infidelity to their subject (or, perhaps, they fear that their peers would accuse them of that).
I can understand this point of view, though it is one-sided: it seems they can see only the ‘topographical distortion’, not the ‘topological correctness’. What I can’t see is why authors who take that view want to write textbooks. The great thing about Beck’s map is it helps people get to where they want to go – which is exactly what textbook authors should be trying to do too.