December 21, 2010

Data Visualization Fail # 3

I found the following chart in one of the reports by a Business Intelligence website which compared the various BI vendors based on different parameters. It chose a Vendor and then compared the Vendor with the Category Average and also the Maximum Category Score. This is a Radar Chart.

Now, lets improvise this chart.

For the sake of keeping things simple(read 'without programming'), i used Excel to show how some amount of effort and care to present 'useful' information would be beneficial for the readers. I quickly wrote down the various readings from the above chart into an Excel Worksheet:
Column1:The Metric Names(like Maturity, Scalability etc);
Column 2: Max Category Score,
Column 3: the vendor,
Column 4: Average Across Vendor),

selected the table data and Insert ... Choose the Column(Bar Chart) and voila get Figure 1.

I find Fig.1 to be much much better and readable than the original Radar Chart. We can easily read how the vendor, the average and the max category score relate to one another. The default colors from Excel are also not bad; though i would have avoided the grid lines and have preferred the number mentioned on top of each of the bars.

But I still could not see the trend - trend in terms of how the Vendor fared w.r.t the others. Then i moved to choose a Line chart and you get Fig2. The line chart with the markers clearly show the trend and how close the Vendor is to the Category Average; and on some parameters, it max'es the Category Score and is purely the market leader.

I hope this simple example clearly demonstrated how good visualization techniques can help in better understanding and interpretation.
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