Unit 16 | Assignment - Data Journalism and D3

Background

The editor wants to run a series of feature stories about the health risks facing particular demographics. She's counting on you to sniff out the first story idea by sifting through the latest information from the U.S. Census Bureau and the Behavioral Risk Factor Surveillance System.

Your Task

Level 1: D3 Dabbler

You need to find a correlation between two data variables, each measured state by state and taken from different data sources. You'll then visualize the correlation with a scatter plot and embed the graphic into an .html file. You need to accomplish these four steps.

1. Find the Data

Look for demographic information using the 2014 one-year estimates from the U.S. Census Bureau's American Community Survey. You can specify your information using the American FactFinder tool. When searching through the data, be sure to select these options in the left sidebar:

• Topics -> Dataset -> 2014 ACS 1-year estimates

• Geographies -> Select a geographic type -> State - 040 -> All States within United States and Puerto Rico

When you select those filters, use the search bar to chose the demographic of your choice, or browse through the entries already shown. Click the data that interests you and then download the .csv file.

Next, you'll search for data on health risks using 2014 survey data from the Behavioral Risk Factor Surveillance System. Note that we already filtered the data by year and break-out—you just need to find the behavioral risk you want to use. Filter the Question data on the site before downloading a specified .csv, or simply download the whole .csv file and use Excel's filtering tools.

2. Format and Test the Data

Let's format your data for D3. With your two data types chosen, grab the value columns from each and paste them into a new Excel document. Create header names that you can easily call with JavaScript (concise, lowercased, camelCased). Make sure that your rows and columns line up—You may need to delete Guam from your datasheet so that your Census and BRFSS data matches.

To make sure you have a solid trend, you need to test for correlation with Excel's =CORREL() function. Aim for a value either less than -0.5 or more than 0.5—these values would indicate a moderate correlation and a story that might be worth pursuing (shoot for -0.75 or 0.75 if you're feeling super diligent).

When you find a suitable match, delete any correlation cells from your sheet and save the file as data.csv. Place it in the data folder of your homework directory and move onto the next step.

3. Visualize the Data

Using the D3 techniques we taught you in class, create a scatter plot that represents each state with circle elements. You'll code this graphic in the app.js file of your homework directory—make sure you pull in the data from data.csv by using the d3.csv function. Your scatter plot should ultimately appear like the image at the top of this section.

• The x-values of the circles should match the demographic census data, while the y-values should represent the risk data.

• Include state abbreviations in the circles.

• Create and situate your axes and labels to the left and bottom of the chart.

• Generate this chart in the d3.html file in your assignment directory.

• Note: You'll need to use http-server to display the graphic since you're pulling data in from a source outside of your app.js file.

4. Embed into an iframe

When your d3.html displays the graphic just as you'd like it to, embed it in index.html with an iframe. Add a quick written analysis of your data below the graphic.

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