In chapter 1 of Envisioning Information, Tufte describes the challenges of representing multi-dimensional (more than 3 dimensions) information in a “flatland” or 2D space. Some strategies he provides for making this task easier include using symbols/icons to compress more data, and including multiple dimensions of data along a single axis in the 2D space. The strategy that Tufte focuses most on in chapter 1 is that of small multiples, which uses repeating design structures to provide another dimension of information and encourages local comparisons. Tufte writes, “this constancy of design allows viewers to focus on changes in information rather than changes in graphical composition.” I think the graph of air pollution in california conveys idea of small multiples the best because it doesn’t have too many multiples, so it is not overwhelming, and it is also easier to see the differences across time periods because the individual graphs are relatively close together and can be viewed all together.