# What kind of chart is this?

Sorry for the vague question but this chart appears in Biddle et al. 2009 and I've not encountered anything like it before. It's a bar chart with beveled edges, sometimes 'horns'. What do these mean? Does this type of chart have a name?

Most statistical packages will let you add these as an option when drawing boxplots, for example in R the boxplot command has the argument notch. Note that there are various subtly different methods of calculating the notches which may vary between implementations.