Comments on: BI FAIL #2 http://timoelliott.com/blog/2009/09/bi-fail-2.html Timo Elliott's Business Analytics Blog Fri, 10 Feb 2012 13:24:00 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Andreas http://timoelliott.com/blog/2009/09/bi-fail-2.html/comment-page-1#comment-3855 Andreas Tue, 22 Sep 2009 23:20:38 +0000 http://timoelliott.com/blog/?p=1250#comment-3855 I can only say, what a poor visualization, to repeat myself: Not only are slices/angles in a pie chart hard to distinguish for the human eye (humans can distinguish very well length and position, that is why 2-d bar charts, 2-d line charts, and xy charts work so well), but the 3-d look makes it even harder as it obscures slices, and the angles of the slices are distorted. I can only stronlgy recommend to go with a 2-d plain horizontal bar chart, where the bars are sorted in descending order according to the measure (see http://www.perceptualedge.com/example12.php) Stephen Few has an excellent website for "information visualization": www.perceptualedge.com I can only say, what a poor visualization, to repeat myself:

Not only are slices/angles in a pie chart hard to distinguish for the human eye (humans can distinguish very well length and position, that is why 2-d bar charts, 2-d line charts, and xy charts work so well), but the 3-d look makes it even harder as it obscures slices, and the angles of the slices are distorted.

I can only stronlgy recommend to go with a 2-d plain horizontal bar chart, where the bars are sorted in descending order according to the measure (see http://www.perceptualedge.com/example12.php)

Stephen Few has an excellent website for “information visualization”: http://www.perceptualedge.com

]]> By: Seth Grimes http://timoelliott.com/blog/2009/09/bi-fail-2.html/comment-page-1#comment-3851 Seth Grimes Mon, 21 Sep 2009 14:43:04 +0000 http://timoelliott.com/blog/?p=1250#comment-3851 Timo, thanks for picking up on my blog article. There are significant BI failures on the GSAspending.gov that are less visible than the graphics problem caused by the misuse of the Google Chart API but as important if not more. The biggest is incomplete and missing information. It is clear that records that are supposed to be and that are claimed to be there are not, for instance, about the U.S. government's fiscal year 2009 contract spending on USAspending.gov itself. That's an example of missing information where there's no hint that it's missing. Incomplete information: the site doesn't include subcontract records. My *guesstimate* is that double-digit-percentage U.S. federal government contracting revenue goes to subcontractors. Without this information, the site is incomplete and gives a very misleading picture where federal money goes. Seth Timo, thanks for picking up on my blog article. There are significant BI failures on the GSAspending.gov that are less visible than the graphics problem caused by the misuse of the Google Chart API but as important if not more.

The biggest is incomplete and missing information. It is clear that records that are supposed to be and that are claimed to be there are not, for instance, about the U.S. government’s fiscal year 2009 contract spending on USAspending.gov itself. That’s an example of missing information where there’s no hint that it’s missing. Incomplete information: the site doesn’t include subcontract records. My *guesstimate* is that double-digit-percentage U.S. federal government contracting revenue goes to subcontractors. Without this information, the site is incomplete and gives a very misleading picture where federal money goes.

Seth

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