choropleth map

The purpose of this assignment was to produce four maps in one illustrator document using two different methods of classification to map the total population, and percent population of people in North Carolina who claim American Ancestry.  The maps are as follows:

Map 1: Absolute number of persons reporting American ancestry; Quintile classification; 5 classes

Map 2: Absolute number of persons reporting American ancestry; Equal Interval classification; 5 classes

Map 3: Percentage of all persons reporting an ancestry that reported having American ancestry; Quintile classification; 5 classes

Map 4: Percentage of all persons reporting an ancestry that reported having American ancestry; Equal Interval classification; 5 classes

The only major struggle of this project was the tedious colorization of each individual county in North Carolina based on its data.  Because I did not know the location of each county, an online source acted as my aid.   The data used was provided in an excel sheet, and all that needed to be done was to sort the data based on the classification techniques.  Sub-classes were then assigned a color using colorbrewer online. 

One requirement of this project was to include a short paragraph (a few sentences) that mentions the ethics involved in selecting a classification scheme (choosing one that best visualizes the distribution of the phenomena being mapped). This paragraph is included in the map image, but is as follows: 

The type of data classification that is chosen can greatly alter the representation of the data. In this assignment, It can be see that the quintile method always makes the classifications appear equally represented, when the actual data could suggest otherwise. The Equal Interval Classification is different in that it uses actual data in the breaks rather than a data’s rank. Overall, it can be seen that data classification types can easily mislead a reader and inaccurately display the true data. It is also important to note that type of data can could also mislead a reader. For example, in this assignment, if deciding to use percentage data, one could make Ashe County appear to have a large number of people claiming american ancestry, where in reality it actually has one of the fewest number of people (as can be seen by map two). Different data types and data classifications can more accurately represent certain types of trends. In this assignment, Map 4 most accurately represents the trend being mapped because it shows which areas more commonly refer to themselves as of american descent. If map two were used, the trend would twisted to make the reader believe the majority of people who do refer to themselves as of american descent only live in Wake county, while in reality the majority of that counties’ population does not.

Discussion:  One flaw in the map is the visual hierarchy.  In order to maintain legibility, it was necessary to make the individual maps larger eliminating room for an appropriately sized title.  Ideally, the title should be slightly larger in order to stand out over other objects such as the legends.  However, the sacrifice in visual hierarchy resulted in a higher level of legibility, although it may have been possible to satisfy both aspects.