Chapter two talks about six principles that help you to achieve graphic integrity. These principles help you to create a truthful and effective graphic.
These six principles are:
- The representation of numbers on the graph has to be directly proportional to the numerical quantity you are expressing.
- Make sure the graphs are thoroughly labeled and explained.
- Make sure you show data variation, not design variation.
- When looking at time-series displays of money, use deflated and standardized units of monetary measurement—not nominal units.
- Using varying dimensions is inefficient. The number of info-carrying dimensions should not be more that the number of dimensions in the data.
- Do not quote data out of context.
The part of this chapter that I found most interesting was the section on distortion. I liked the idea of conducting experiments on perception. Perception of area is not the same for every person, and it makes sense to me that people can be influenced by their surroundings. I also found the part about the lie factor to be interesting. It was interesting to be able to apply a formula to help better understand how misleading the graphs really were. It makes the impact so much greater, when you can apply a direct number to represent the distortion.
In chapter 3, Tufte talks about sources of graphical integrity and sophistication. The question being posed in this chapter is ‘why do artists draw graphs that lie’? He answers this question using three principles: the artists do no possess enough quantitative skill, the are trying to avoid making the graphs appear boring, and they feel that graphs are only used to entertain those who cannot handle text. The part of this chapter that stuck out the most to me was the small section on college and high school textbooks. The statement that textbooks often contain more sophisticated graphics than news publications surprised me. I also found the part about the Japanese children’s statistical graph contest to be interesting. It shows why Japan is at the top of the list; the children learn these skills at such a young age.