The New York Times is one of the more interesting innovators when it comes to using data visualization to tell a story or make a point.  In particular, the Business section employs a variety of chart forms to reveal what is happening in financial markets.  The Weather Report uses “small multiples” to show 10-day temperature trend for major U.S. Cities.

Even more interesting are the occasional illustrations that appear under the heading of “Op-Chart.”  For a few years now the Times periodically presents on the Op-Ed page a comparative table that tracks “progress” in Iraq on a number of measures such as electric power generation.

Another impressive chart appeared in “Sunday Opinion” on January 10, 2010.  Titled “A Year in Iraq and Afghanistan,” this full page illustration provides a detailed look at the 489 American and allied deaths that occurred in Afghanistan and the 141 deaths in Iraq.  At first glance, the chart resembles the Periodic Table of Elements.  Deaths in Iraq take up the top one-fourth or so of the chart (along with the legend); deaths in Afghanistan occupy the bulk of the illustration.

Each death is represented by a figure, and each figure appears in a box representing the date which the death occurred. One figure shape represents American forces, and a slightly different shape signifies a member of the coalition forces.  For coalition forces, the color of the figure indicates nationality.  A small symbol indicates the cause of each death (homemade bomb, mortar, hostile fire, bomb, suicide bomb, or non-combat related).  Multiple deaths from the same event or cause on a date occupy the same box.

Most dates have only a single death, but a few days standout as particularly tragic:  seven U.S. troops dying due to a non-combat related cause in Afghanistan on October 26; eight killed by hostile fire on October 3rd; seven killed by a homemade bomb on October 27; six Italians killed by a homemade bomb on September 17; five Americans killed by a suicide bomber in Mosul, Iraq, on April 10.

The deaths are linked to specific locations on maps of Iraq and Afghanistan.  Helmand Province was the deadliest place, with 79 of the 489 deaths in Afghanistan.  In Iraq, Baghdad was the most dangerous place, accounting for 42 of the 141 deaths in that country.  While Americans are the largest number, 112 of the dead in Afghanistan were British troops.

There is a wealth of information in this chart with four pieces of information on every death, but in some ways there is too much detail.  To get at the numbers I provided above, I had to manually count the pictures.  There are no summary statistics.  The picture grabs our attention, and immediately conveys the magnitude of the price the U.S. and our allies are paying in Afghanistan.   But if we want to act on data, we need a little more than just a very clever visual display.  Summaries of the numbers would help, here.  It’s useful to know, for example, that 65 of the 141 deaths in Iraq (46%) were due to non-combat related causes, compared to 48 (10%) of the deaths in Afghanistan.  Eighty percent of the fatalities in deadly Helmand province were due to hostile fire; 57% in other parts of Afghanistan were caused by homemade bombs (in Iraq there were 19 deaths, or 13% of the total, from homemade bombs).

Two of the creators of this chart, Adriana Lins de Albuquerque (a doctoral student in political science at Columbia) and Alicia Cheng of mgmt.design, produced a slightly different version of this chart summarizing the death toll in Iraq for 2007 (click here).  That earlier version did not have as much detail about each individual death (location information is not included, for example) but includes some additional causes, like torture and beheading that, thankfully, appear to have disappeared.

The advantage to displaying data in this fashion lies in the ability of our brains to form patterns quickly.  The use of color to designate coalition members makes the contributions of our allies apparent in a way that a simple tally might not.  Even without a year-to-year comparison, we can see that Iraq has become, at least for US troops and our allies, a much safer place than Afghanistan.  Additionally, this one chart presents data that, in other forms, might require several PowerPoint slides to communicate: deaths by date, deaths by city or province, deaths by nationality, causes of death, number killed per incident, and cause of death.

Any complex visual display of data requires making trade-offs.  In this case, for example, the creators arranged the deaths chronologically (oldest first) within each geographic block.  That means that patterns in other variables, such as cause of death or nationality of troops, may be harder to detect on first glance.  The chronological ordering has layout implications, since on some dates there were multiple casualties.

All in all, it’s a great piece of data visualization that to my mind would be even better with the addition of a few summary statistics.

A disclaimer–I counted twice to get each of the numbers I provide above, but I offer no guarantee that I am not off by one or two deaths in any of those numbers.

Copyright 2010 by David G. Bakken.  All rights reserved.

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