I believe the most important concept mentioned in Ch. 1 is the idea of tabular arrays of numbers (data entries). The viewer is able to absorb a lot of information in a straight forward and easy way. The best example they give is the Law School aptitude test percentile. It shows GPA and LSAT scores. This type of information display is still used frequently. I saw it used a lot when I was applying to college. The graphs would show me the average GPA range, and the acceptance percentage to a particular college. It was very helpful and interesting to see.