For this lab assignment, I used Tableau to clean some data referenced in my Finding Data post and to create graphs from these data. I visualized two data sets: Median Household Incomes (1979–1989) of Alabama Counties and Individual Contributions to the 1980 Presidential Campaigns. Note that the data I used for the Contributions Graph is different from the example data referenced in the Finding Data post because I wanted to capture information encompassing both the Reagan and Carter campaigns of 1980.
Median Household Incomes (1979–1989) Graph
This graph portrays in 1989 dollars the median household income of each Alabama county in 1979 and 1989. I included a median income line, which represents $20,300, to provide some reference for the amounts. It is easy to see from this visualization which counties have higher median household incomes than others, and how they compare to the median household income of the state over both years, a value calculated by Tableau.
This graph emphasizes the percent change in median household income of each county from 1979 to 1989 as discrete values; the interval is not continuous, which means that the years 1980–1988 are not considered in the calculation. I color-coded the values—red for reduction and green for growth—so it is easy to see the direction in which each county experienced an income change from the 1979 value and the 1989 value. While most households in aggregate experienced an increase in median income, a considerable minority did not.
Individual Contributions to 1980 Presidential Campaigns
This treemap chart illustrates proportions of individual contribution counts to the Carter and Reagan campaigns by Alabama city or town. I created this chart to discuss its strengths and weaknesses. It is easy to see that the majority of individual contributions came from Birmingham, Mobile, Montgomery, and Tuscaloosa and that the Carter campaign received the most occurrences of contributions. However, it is hard to see which counties besides these four contained individual contributors. The chart segments become too small to display the city or town names and count numbers. This graph should not stand on its own.
This chart is a better visualization of the data shown in the treemap chart. It shows by Alabama city or town the number of individual contributions to the Carter and Reagan campaigns with total amounts from each location. The locations listed are organized in descending order based on the number of individual contributions to both campaigns. The gradient color visualization highlights those cities with the highest total contribution amounts, but because of the graph’s layout, it is easy to see how many contributors came from each listed location and the total contribution amount from each listed location by campaign. This is a more detailed chart that can present a fuller picture.
It is important to note for both of the contribution charts that I had to merge some values for cities due to typos on behalf of the individual (e.g., Birmingham was spelled Birminham and Birmington, Tuscaloosa was also spelled Tuskaloosa). I checked these against the ZIP code for each entry. Some of the locations have since been renamed or reorganized, but I left those as is (e.g., Langdale is now part of Valley). A small number of locations I could not identify as proper cities or towns, but I left those also as is (e.g., I do not know where Chatch is).