Cartographic Skills: Final Project

SAT Mean Test Scores and Participation Rates in the United States - 2013

The SAT, or Scholastic Aptitude Test, is the standardized admission test most commonly used
by colleges and universities in the United States (College Board, 2014).  High school students may also choose to take the ACT test and both tests are equally accepted.

For the final project in Cartographic Skills class, we were given a web link to SAT score and participation rates for the fifty United States and District of Colombia.  We then created a single map to represent both datasets.  I used a chorpleth map to represent the mean scores for the states, with five classes and the Jenks Natural Breaks method.  For the percent participation, I used a proportional symbol scheme.  The participation rates range from 2% to 100% and I decided that it was not necessary to employ a square root or cube root factor to reduce the size range of the symbols.  The significant variation in SAT participation rate is well depicted with a direct proportional representation.  An inset map was necessary to detail the smaller northeastern states because their relatively large proportional symbols would otherwise obscure them on the map.

The most striking data characteristic that might be taken from the map by the user is the strong negative correlation between participation rate and mean SAT score.  The seven states in the central U.S. that make up the highest score class (dark blue) also have low participation rates.  The three states with lowest scores have nearly 100% participation as a group.  Without this dual data display, the map reader might be left with the impression that some states have much better-educated high school students.  In order to have a truly useful map display, however, it would be necessary to pair this map with a similar one covering mean score and participation rates for the ACT. Some states which have a very low SAT participation rate have a very high ACT participation rate; for example, only 3% of high school graduates in Wyoming take the SAT, but 100% take the ACT test.

Data Sources:

ACT.org (2014). 2013 ACT National and State Scores.
Retrieved from http://www.act.org/newsroom/data/2013/states.html.

College Board (via Connecticut Department of Education, 2014). Mean SAT® Critical Reading,
Mathematicsand Writing Scores by State, with Changes for Selected Years. Retrieved from
http://www.sde.ct.gov/ sde/lib/sde/pdf/ evalresearch/ ct_sat_public_schools_2013.pdf.