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In the fall issue of USAA’s magazine, I came across the chart below that shows fatal crashes, per 100 million miles driven and per age group.  I found it interesting, yet logical, that sixteen year-olds and those aged eighty-five plus, have the most fatal crashes. 

What concerned me about this chart is how distracting the non data-ink appears.  Here are the top issues I see with this chart:

1. The picture in the background.  It contains a picture representing each of the different age groups.  The graphic is not needed to convey the message properly.
2. The horizontal grid lines in the bar chart (chartjunk).  They are definitely distracting and take away from the data points.  Plus, there are no quantifiers on the Y axis to make them semi-useful. 
3. The yellow bar is difficult to see.
4. The cars are not needed at the top of the bars.
5. The data is not really insightful.  The only thing I can quickly understand is that the first and last category are a lot more than the middle one.

 

One hundred million miles sounds like a huge sample size, right?  Not really!  If the average driver travels 15,000 miles a year, then that’s only tracking roughly 6,700 drivers per age group over a year.  I would have expected the sample size to be much larger to make the study more statistically significant.

As software gets more sophisticated, charts and graphs seem to take on a whole different look and feel.  However, the one constant is the data.  Products such as Crystal Xcelsius can reduce the effectiveness of data visualization if used improperly.  It becomes more about how “pretty” we can make a bar chart or gauge look versus simplicity.  I’m sure you’ve heard the adage, “…lipstick on a pig”.  As a businessperson, I want to quickly and accurately understand what a data series is telling me. 

Alternatively, I also understand that many executives and the average person is intrigued and sometimes in awe of these “tasty” data representations.  That’s where balance and a true analytics expert can bridge the gap between what is simple, yet appealing and effective.

PART II - September 27, 2007 

I checked the source: Insurance Institute fro Highway Safety for this article.  The only reference to this study was found at this location, (you need to click on #4 to open up the text) which was from 2001-2002.  The dark black line represents fatal crashes per 100 million miles traveled, similar to the USAA article.  Looking at the line graphs, it quickly becomes apparent why they chose the age ranges they did.  The shock factor!  Between 30 and 65, the line is clearly flat, thus no “earth shattering” story…

 

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This entry was posted on Wednesday, September 26th, 2007 at 11:16 am and is filed under Analytics, Chartjunk, Presentation, Reporting, Tony. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.