Computer Cartography - Finally Done!

This final project was designed to utilize the cartographic skills, methods, and principles that were learned throughout this course.  To illustrate mastery of these skills, a complex map depicting multiple layers of data was created.  The data used to create this map were the 2014 nationwide average SAT scores for each state as well as each state’s student participation percentage in taking the SAT.  By mapping these two pieces of data together on the same map, it could show a correlation between SAT scores and how many students actually participated in the testing. 

To create a map that depicts two different sets of data, two thematic methods were chosen to provide enough distinction between the data sets.  The two thematic methods used were choropleth mapping using graduated colors for the average composite SAT scores in each state and proportional symbol mapping using graduated symbols for the participation percentage. 

            The data for the state average SAT scores needed to be combined into a composite score as it was provided as the three SAT section scores.  No normalization of the composite scores was applied to the data.  Once these scores were combined for each state, the resulting composite scores were used to create a choropleth map of the United States.  Graduated color symbology was used in ArcMap to achieve this.  The data was also divided into five groups, or score ranges, using the quantile breaks method.  This was used to ensure an equal number of states was in each group, providing some color differentiation and even balance to the overall map.  The color ramp for this data series was red (lower SAT scores) to green (higher SAT scores

            The participation percentage data was taken directly from the source document and no manipulation or normalization was required for mapping.  To map this data, proportional symbology, in the form of graduated circles, was used to map the participation percentage on top of the existing choropleth map for the average scores.  A light blue circle with a black border was used to contrast the color scheme of the base map.  The actual percentage was also placed inside the circle to clearly show the data on the map.  For this symbology the data was divided into five groups, however using natural breaks instead of quantile.  

            As one looks at this map, you can quickly see that the states with the higher average composite SAT scores also happen to be the states reporting the lower participation percentage.  One could assume that only smarter students are encouraged to take the SAT’s in these states where as the states with the lower averages and higher participation rates have their average scores brought down by more average students.  One could also assume that if the states with lower participation rates were to encourage more students to take the SAT, their average composite scores would also come down and fall more in line with the higher participating states.  

          So this map brings this course to an end.  I will say that of all the GIS coursework I have done up till now, this has been one of the more frustrating courses for me.  I think that is because a lot of the evaluation has been subjective in interpretation.  That combined with being colorblind, application of certain principles has proven to be quite challenging.  This is definitely hasn’t been as easy as just obtaining data and creating a map from it.  That being said, I have learned a lot and I guess the Marine in me gets enjoyment and fulfillment from challenging and frustrating situations.