P.Mean:  A misleading bar graph (created 2008-07-15)

A regular contributor on EDSTAT-L, found an interesting bar graph on the DirecTV website.

Notice that the bars are 28, 36, and 67 pixels high, respectively (my measurements are approximate). Since the height of the first two bars is less than the height of the second two bars, this gives the false impression that DirecTV has more Cable and Dish Network combined. The height of the second bar is about half the height of the third bar, giving a false impression that DirecTV has almost twice as many channels as Dish Network.

All of this could simply be chalked up to a failure of the advertiser to recognized the importance of anchoring the bottom of a bar graph at zero. But one more discrepancy makes me think that the advertiser wanted to provide an intentionally distorted picture. The difference in heights between the first and second bars is 8 pixels, which corresponds to a difference of 25 HD channels. The much larger difference in heights between the second and third bars is 41 pixels, which corresponds to a difference of only 14 HD channels. This gives the false impression that both Cable and Dish Network lag far behind DirecTV. If the difference in heights was consistent, then it would give the impression that Dish Network and DirecTV are close, with Cable lagging far behind.

Creative Commons License This work is licensed under a Creative Commons Attribution 3.0 United States License. This page was written by Steve Simon and was last modified on 2010-04-01. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Graphical display.