One simple trick to improve (some) bar graphs

I ran across this figure because it was being used as a good example.

This is a journal figure, not a poster figure, so there are many things I would want to do differently on a poster. But I just want to focus on one thing:

The most important things to read on this figure are the labels on the x-axis. You’re probably crooking your neck right now trying to do so. Readers should not have to contort themselves to read your graph.

For that matter, the all the y-axis labels also require you crook your neck read them. Even the numbers, which have no business having their being vertically aligned.

But luckily, the solution is simple: rotate it!

Suddenly, this graph becomes easy to scan. No information is lost. The data is not harder to compare. And by definition, the graph takes up the same amount of space on the page. Some tweaking might be required to optimize to columns widths, though.

There are a couple more changes besides rotating the entire image. The old y-axis scales are on the top with a simple rotation, and those got moved to the bottom. The legend and the comparison letters, which were the only things oriented horizontally, got “unrotated” back to horizontal.

If your labels are too wide to be horizontally aligned, consider turning your vertical column graph into a horizontal bar graph.

You don’t want to do this in every case. If you are plotting time as a variable, it is almost always better to keep time on the x-axis, because that is such a standard way of portraying time in graphs. Fortunately, you can often use abbreviations for time (“Jan” or even “J” instead of “January”) to avoid vertical text.

I can’t help you with those taxonomic names, though.

And the moral of the story is: English text wants to be horizontal!

Reference

Seppey CVW et al. 2020. Soil protist diversity in the Swiss western Alps is better
predicted by topo‐climatic than by edaphic variables. Journal of Biogeography 47:866–878. https://doi.org/10.1111/jbi.13755