This weeks assignment: data manipulation

This weeks assignment in the MOOC on infographics and data visualization by Alberto Cairo is about maps. From his new to appear book we have to read the fourth chapter on Cartography for Journalists, or as the chapter title reads: Thematic Maps, Statistics and Cartography Meet. Like his earlier book – The Functional Art -, also this chapter is a well written piece with many great visuals.1 Alberto Cairo describes thematic maps as “the purest and most successful form of information graphics”, and I certainly do not disagree. And about the assignment? That is to use data from the data from the US Bureau of Labor Statistics and show unemployment in the US. In a way like The Guardian’s Data Blog published a story about unemployment in the US: http://www.guardian.co.uk/news/datablog/interactive/2011/sep/08/us-unemployment-obama-jobs-speech-state-map. But with more functionality and depth.

With Tableau, TileMill, or even with ESRI ArcGIS online this task is not that big. The data is easily accessible and well-organized. But this is exactly where standard mapping differs from making infographics. I am quite sure that our teacher does not want the standard map. In the first assignment I created a map and Alberto commented: “However, it doesn’t improve the original as much as it could. The reason is that you are forcing me to click on each country to get the data, rather than giving me the opportunity to explore the data in different ways, such as creating rankings, comparisons between countries, etc.”. So no standard map this time, but something that will focus on the exploration.

I decided to focus on two of the questions that are raised in the assignment:

  • What kind of graphs or maps would you need to tell a compelling story based on this?
  • How would you give context to the data?

If we are talking about unemployment during the first period of Obama there are  some nice infographics on this subject already in the run to the elections.

My approach: Geo Tagging

The latest data available is from September 2012 and looking at that data you immediately see the big differences between states. Montana, Wyoming, North and South Dakota, Nebraska. From my times being there I know the views of large (or even more than large) plains, the emptiness. The number of people per square meter must be very low. On the other hand the giant peak in California, and the higher (but not peak) values in the dataset for states along the east coast, and the big cities like Chicago, Detroit, and states like Texas, and Florida. My first impression of the dataset is that it is not averaged by population density.

In order to map the data, and to show the population – unemployment relation the data must be geo-tagged. Since the data is ordered by state, and the state codes are given this is not a difficult task. MaxMind offers a nice table of states and their longitude and latitude. By combining this data with the given data set I now at least have point data that is geo referenced. And so it can be mapped with a centroid.

Then I started to play with tableau public. Within the map option of the software there are several settings and datasets preloaded, population, population by race, occupations.

What appears to me is that population density and mixture of race both have effects on the figures. States with many big cities seem to have a higher unemployment rate. So a first step would be to map the data against the population density.

The Census Bureau Data

The United States Census Bureau has a nice dataset for the census of April 2010. Although the census data is for the full population, including those people that are too young to work, or those that are retired the figures change already with the first quick lay-out. Rhode Island that at first was a small dot, now suddenly becomes one of the largest. On the other hand California that seemed to be the state with an incredible high unemployment rate now has become an average player. All in all we see how the differences have become smaller when it comes to the percentage of the total population that is unemployed.

Conclusion and the final result

So “to tell a compelling story” I made an interactive infographic where the map is a main element on the page. From this map you can click on a state and see the unemployment figures for 10 periods in time: at the start of the first period of Obama, and then each year, until just before his re-election. The context is that data is multi interpretable, even though everyone knows the facts. By leaving out specific details data manipulation becomes a word with a double meaning.

ps. Did I tell you that subscription to the second course, starting in January is open? You can subscribe here: Knight Center for Journalism in the Americas’s Distance Learning program.

1 In the first version this paragraph read: “From his book we have to read the fourth chapter on Cartography for Journalists, or as the chapter title reads: Thematic Maps, Statistics and Cartography Meet. The book is well written with many great visuals and the same is true in this chapter.”

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