Quiz 6 Discussion (Week 3) | GeoNet
(Illustration from Penn State University GEOG 487: Cartography and Visualization https://www.e-education.psu.edu/geog486/ Open courseware © 2014 The Pennsylvania State University licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.) Explanation: Answer 2 – MAUP – is best. The illustration shows three identical point distributions aggregated to three different sets of boundaries, leading to three very different patterns. It’s true that the illustrations include choropleth maps (Answer 1) and point symbol maps (Answer 4), but it’s the difference between the map patterns that’s illustrative. Yes, the points are plotted on the areas, but that isn’t overlay analysis. Finally, consider a thought experiment: In which of the three choropleth maps (if any) is data normalized? Explanation: Answer 4 is correct. This is an important bit of jargon when talking about aggregating data for thematic mapping. Explanation: “Boundaries and scale” is correct. The boundary effect of MAUP is illustrated in Question 1. The scale effect would be evident if we were to compare calculations of the density of points for the entire area with densities within its subdivisions. The point is to choose the scale of analysis that’s most appropriate for a given research question. Explanation: The first answer is correct. The rest may be true, but they are not directly related to MAUP and are perhaps not as compelling on their own. (Illustrations from Penn State University GEOG 482: Nature of Geographic Information https://www.e-education.psu.edu/geog482/ Open courseware © 2014 The Pennsylvania State University licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.) Explanation: Maps 1 and 3-5 display aggregate data with different kinds of point symbols. Choropleth maps, such as the example in Map 2, use colored and/or shaded areas to symbolize aggregate thematic data. Question 6 asks, “One of last week’s lectures described an analysis of cell phone tower locations combined with population summaries. In the map below, towers are symbolized with blue points, and summarized population counts are shown as orange points. Why use point symbols for population? Why not simply color each area to represent the population counts?” Explanation: Answer 3 states the cartographic convention for choosing between point and area symbols. The “Colors are better because…” answer argues for an exception to the convention. There is an exception to every rule, but probably not in this case. “Point symbols imply that population is concentrated…” may be true for a few naïve viewers, but that’s not reason enough to overrule the convention. “Differences in the fine gradations of color are easier to see than differences in the sizes of proportional point symbols” is simply untrue. And if you think “It doesn’t matter…” is correct, take it up with our guest speaker, cartographer Ken Field. Source.