In reply to Dirk Schomburg.

Thanks for writing. Yes, I understand what you are saying. Sorry if I was not clear. I think what I was trying to convey in the second paragraph is that most people use the bar chart to display empirical (observed) counts. As you correctly point out, the CIs are for an underlying population parameter, not for the sample. If your audience will understand the difference, you can use a bar chart to display expected counts (which are often not integers) and the CIs.

The main point of the article is that many people use the bar chart to display means and CIs. I suggest using a dot plot instead. In addition to the arguments I made, Peter Flom in the first comment links to a poster by Tatsuki Koyama that contains additional reasons to avoid a bar chart with error bars when your goal is to visualize the uncertainty in the estimate of a mean (or a proportion).