Application of Data Visualization: Political Polarization in the American Public
Tags: Data Analysis, Political Satire, Data, Data Science, Data Visualization

Data visualization could help people easily understand the meaning of the raw data extracted from multiple sources. In general, in order to briefly present the data, how to choose the different chart to present the data is essential. This article will give an example to demonstrate how a research report to choose appropriate charts.

The research studies political polarization in American public by tracking people’s ideology. This study tracks the trend from 1994 to 2014 and presents what the shift of people’s perception of Republican and Democratic. In this research, we could see how data visualization helps people understand people’s perception changed over time. It’s a good application of data visualization that people could easily learn the shift when those figures show the population with different levels of consistent ideological view by distribution, histogram, clustered column, stacked area, bar chart and stacked column.

Application of Data Visualization

1. Distribution

In Figure 1 below, we could see the distribution of Democrats and Republicans on 10-item political scale. The figure uses both the median Democrats and the median Republicans as criteria to define the ideological overlap between the two parties. With the data visualization, we could clearly see the overlap increased in 2014. And the report points out that “ 92% of Republicans in 2014 were to the right of the median Democrat, and 94% of Democrats were to the left of the median Republican.”

Figure 1 Distribution of Democrats and Republicans

2. Histogram

Then the article analyzes the people’s attitude toward other party. In order to compare how the attitude of people who either are Democrats or Republicans change over time, we need to separate the two parties and quantify people’s feeling. To present the accurate representation of distribution to compare two groups, the article chooses the histogram. In the histogram, we can clearly see that “the share with a highly negative view of the opposing party has more than doubled since 1994”.

Figure 2 Negative view of the opposing party

3. Clustered-Column

In order to identify “Ideological silos”, the article uses the clustered column (Figure 3) to visualize the percentage of people who either always vote or contributed to a political candidate or group in 1994, 1999, 2004, 2011, and 2014. The clustered column usually is used to display multiple data series and each data series is categorized by the different groups to be compared.

Figure 3 Political Activism Gap

4. Stacked Area Plot

The study wants to show the unfavorable impression of the Republic party that the Democrats have and the one of the Democratic party that the Republican have. Also, the study wants to display the components including negative term and strongly negative term. Here, the stacked area plot is a good choice. Stacked area plot could present the evolution of the value of multiple groups sharing the same axial and those groups are the components of an entity. Therefore, we could see not only the individual population of people’s different negative impression and compare to the value of each group in the same figure.

Figure 4 Unfavorable impressions

5. Bar Chart

In order to display measure value of different ideological echo chambers, the article uses the bar chart to show comparisons among those independent categories. The bar chart is a simple way to display the measure value in different groups. In the bar chart, we could understand the largest value and smallest value directly. In Figure 5, we realize that “People on the right and left are more likely to say it is important to them to live in a place where most people share their political views.”

Figure 5 % Liberals and % conservatives share a passion for politics

6. Stacked Column

Here is another famous chart, stacked column. The stacked column could break down and compare parts of an entity in the same graphic. In the stacked column, each bar is an independent entity and the stacked column could display the different parts of the entity. In the article, it uses the stacked column to present people are either Democrats or Republicans with different ideological preference, and the result shows more Democrats takes liberal position and more Republicans takes conservative position.

Figure 6 Polarization in Red and Blue

Conclusion

This article shows how data visualization are presented in 6 commonly used charts. In general, people use a distribution to brief the content of an entity, use a histogram presenting accurate data of the distribution, and use a bar chart to display the measure value in different groups. Also, people present multiple data series are categorized by the different groups to be compared by a clustered column, display the evolution of the value of multiple groups that are the components of an entity by a stack area plot, and use a stacked column to break down and compare parts of an entity in the same graphic. In the article, it is essential to choose the appropriate chart to present the data. With the help of data visualization, it becomes easier for people to understand and get a concept of a situation that raw data has been extracted from.

About the Survey

The data in this report are drawn from the first wave of the American Trends Panel, conducted March 19-April 29, 2014 among 3,308 respondents (2,901 by Web and 407 by phone). There are 3,308 respondents and the margin of sampling error for the full sample is plus or minus 2.2 percentage points.

Table 1 Raw data

Reference

Pew Research Center, “Political Polarization in the American Public”, 2014/06/12