Data Classification

The first few labs focused on the graphic design aspect of cartography now in Lab 4 the focus is gear towards spatially representing data by looking at some of the data classification options available in ArcGIS Pro. 

Similar to the lecture for this module let us start with the easier classification methods, equal interval and quantile.

• Equal interval classification is derived from dividing the range of values by the number of classifications. This is show in the map on the lower-right corner. Although this an easy to understand method it does not represent the density of seniors in Miami-Dade County effectively.
• Quantile interval places the equal number of values in each class. Which is calculated by dividing the number of observations, data points, by number of classes. One disadvantage to this method is tying classes. Since values should not be placed in more than one class it might be necessary to establish manual breaks. 
• Standard Deviation classification groups the values by adding or subtracting the datasets standard deviation. This method might be difficult for some map user to interpreter and is best reserved for when the data is normally distributed. 
• Natural Breaks is the final classification method explored. This method will group data which minimizes the difference between values but maximizes the difference between classes.
  

Presented are the maps which shows the density of senior population in Miami-Dade County. This is accomplished by normalizing the total senior population by the Census tract area. From the form options, it easy to see that the Quantile and Equal Interval do a poor job of representing this type of information. The Natural Breaks and Standard Deviation clearly represent the area of the County with the highest density of senior population. 

However if an effort was made to target seniors calculating the percentage of seniors in a specific area is effective, as show in the map document below. As you can see here the equal interval clearly indicates the areas with high senior population.

Building on the previous labs for this map I wanted to do somethings a bit different. Since the assignment expected four map's the clear design choice is to divide the document into four quarters. Yet that was a bit box for my taste and decided to place the titles, attribution, and scale in a center circular badge. The colors chossen are complimentary values to provide some contrast between the area of interest and surrounding features.

Enjoy!