[R] Can we get rid of bar charts with error bars?

[Jim Lemon]

On 12/04/2009 12:56 AM, Frank E Harrell Jr wrote:
> Bar charts with error bars are far inferior to dot charts and other 
> types of displays.  One of many problems is demonstrated if you draw a 
> bar chart displaying temperature in F then re-draw it on the degrees C 
> scale.  See http://biostat.mc.vanderbilt.edu/DynamitePlots for much 
> more information.  The error bars lull us into an assumption that 
> symmetric confidence intervals are OK, among other things.
>
> Frank
>
I could promote the "dispersion" function as capable of displaying 
asymmetric confidence intervals on whatever location indicators you 
prefer (have a look at the second example for "hierobarp" for example), 
but the problem is deeper than that. The point of graphic displays is to 
convey information to someone else, not to tell ourselves what we 
already know. Do people cheat with pie charts, bar charts, etc? Sure, 
and we could cheat with dot charts, too. Graphic displays are typically 
shown to an audience that knows less about the topic than the presenter 
in the hope that an obscure relationship will be clarified. If I am 
presenting to colleagues in my field, I will use much more informative 
and difficult to understand graphics than if I am summarizing the same 
results to the general public. If both groups leave the respective 
presentations enlightened, I have done well.

Jim