Another image from my 1930s algebra book is on pie charts, or what was then called circle charts. And while the utility of such a chart form has not changed, especially in these examples, the circle chart of the 1930s had one particular good use for students. Constructing it.
Circle chart construction
Today a student plugs in numbers into a spreadsheet in Google Docs, Excel, or Open Office. He or she presses a button and the circle chart is done. Back in the 1930s, students needed to convert absolutes to percentages and then use protractors to draw the slices on pieces of paper. Fancy that, students having to do math to make a chart.
Often we think of graphs, charts, and other forms of data visualisation as a means to exploring the economic growth of so and so, or visualising traffic patterns, of explaining the complexities of science, or the reporting of yesterday’s news. But, we can all use data visualisation in our own lives to help make better decisions.
While I normally opt not to post links to other data visualisation blogs—I figure most people are also already checking those out—Nathan Yau posted about why he wants to cut the cable, i.e. lose his cable television subscription. He has two separate charts that are simple but effective in driving home the point that he really ought to think about cutting cable out.
Cutting cable
The article, while a bit longer than usual, is well worth the read. The charts with the explanation make for a compelling argument.
Mitt Romney lost badly last night. No way around that. But as I watched the results come in through various sources, I noticed two interesting design decisions that made me think; one from the Guardian (the British perspective), and the other from the New York Times.
Using only Colorado as an example, here is the map of county results by the Guardian.
Results map from the Guardian
Note how the map is presented in 3-D that therefore allows the use of height as another encoded variable, in this case the size of the lead. Now compare that to the map used by the New York Times.
Results map from the New York Times
Note how this map is flat. So much less cool, right? But try to compare the results in Denver County. When I look at the Times’ map, I see blue; Mitt Romney won. When I look at the Guardian’s map, I see…actually, I can’t. That label is in the way. And then even when I begin to interact with the map, Denver County is hidden by the height of Arapahoe County.
But what about the size of the lead? I cannot see that encoded in the New York Times map. No, one cannot. However, they added a toggle function to change the data displayed on the map—though the utility of that view can be left for another discussion.
And now to a minor point about comparing the totals.
Again, a look at the Guardian’s presentation.
Results table from the Guardian
And now the New York Times. Numbers are numbers and faces are faces. But look at the graphic element representing the percentage. With the Guardian, I can just barely discern that the size of the circles for Santorum and Romney are not the same. And the same goes for Gingrich and Paul. But when I look at the Times’ presentation, I see a simple bar chart that more clearly shows the relationships between the results.
Results table from the New York Times
So interesting design decisions lead to one view that I find far more successful in showing the data: the New York Times.
Houses are meant to be lived in. Which is good to know if you’re a real estate investor because the housing market in the US is still not so good. According to an article in the New York Times, we’re back to 2003 levels (on average of course) for single-family homes.
Accompanying the article is an interactive chart that lets users view the full breadth of the survey while highlighting specific markets of interest and showing actual values along the length of the chart.
The Case-Shiller Index for Housing Prices
Credit for the piece goes to Kevin Quealy and Jeremy White.
The Republican primaries…they’re still going on…on the long inevitable road to Romney’s coronation. Next up is Florida, always an interesting state to watch. There are a lot of people there with a whole host of interesting demographic slices. Perhaps one of the most interesting ones, at least to the media, is the Hispanic vote. Other things to look at in Florida include the burst housing bubble and rather high unemployment.
The New York Times published a graphic with a few maps and charts trying to paint the landscape of the Florida primary battle. These two selections below show which Republican primary candidates won which counties in 2008 as well as the size of the Hispanic population registered Republican.
The Guardian has an interactive piece that details payments to and from European Union member states to institutions, determining whether each state is a giver or receiver.
Comparing payments and receipts in EU member states
The concept sounds all well and good. However, the piece itself feels clumsy with too much scrolling and whipping about to pan across the whole EU. The charts look a tad heavy—which could have been remedied for a more concise piece—and the callouts beg for a level of interactivity that is otherwise lacking.
Lastly, I have concerns about the list of countries at the top, although these may stem only from the point of view of an American not too familiar with Europe. Flags are not circles, they are, in most cases, rectangular in shape. Does cropping a symbol or icon of a country make it more or less useful of a symbol or icon? Furthermore, do the British recognise the flags of their fellow EU member states?
The country icons/flags call for some type of sorting function, to compare payments and receipts and their balance. But, instead, they sit there in unalterable silence, providing only an economic overview when clicked. An overview that through its staid design feels more like an afterthought.
Simple graphs can tell great stories with little annotations. This graphic by the New York Times illustrates that point well with a stacked line chart set behind a line on the same scale. The two should match, or at least the red should be beneath the greys. When they don’t, you have a story and the Times calls it out.
The Iraq War is over. And now it is time to reflect on what we have gained and what we have lost. This map by the Guardian details the number of soldiers killed in action in Iraq. (Other options include total wounded, killed by non-hostile, &c.)
Killed in Action in Iraq by State
Unfortunately, I call it a ‘no kidding’ type of map. The data, accessible via the Guardian here, corresponds nicely with a list of states by total population. Of the top ten countries in KIA, only Virginia is not among the top ten in population; it is 12th. The country thus not in the top ten in KIA, but in population is North Carolina. It’s rank in terms of KIA? 11th.
The data is interesting and worth depicting if we are to reflect. But, perhaps a more suitable visualisation could have been chosen.
On a personal note, these Google Maps overlays are annoying when, in the cases of, e.g., Wisconsin and Massachusetts, the shapes are incorrect. Perhaps coastlines are not as easy as states with ‘straight lines’ for boders, but we would do well to try and make irregular coasts at least somewhat correct.
