A blogger was dissatisfied with the "official" version of a graph measuring course elevation by mile throughout the Boston Marathon (bottom graph). He recorded his own data, and through a small multiples comparison, asserted that his graph (the top graph) was more precise. He points to the portion of the graph between miles 15 and 23 where the official graph smooths out the smaller hills. Not only is the actual wave much more precise (which means that elevation was recorded at very small intervals of distance) in the top graph, but it involves more precise binning on the vertical axis, has distance markers on the horizontal axis (unlike the bottom graph), and is presented on a lined background that allows the viewer to easily identify the x, y coordinates of each point on the graph.While I appreciate his graph for being a more precise rendering, his choice to use different binning and page dimensions makes it difficult to compare the waves in each of the graphs. For example, it is difficult to find a pair of points, comparable in their x, y coordinates, and observe how one point composes a smoothed wave and the other composes a more precise wave.
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