This graph shows the density of osteocytes, or bone cells, in different parts of the calcaneum (heel) of a mule deer. Cranial, caudal, medial, and lateral translate as front, back, inside, and outside.

The biggest problem is that the arrangement of the bars doesn't correspond with the parts of the bone in question. Nor are the colors of the bars meaningful; they're only there to make the legend work. The cryptic y-axis label is just number of osteocytes per square millimeter. The three cases where there are significantly more osteocytes are indicated on the graph with an asterisk (*), the conventional indicator of statistical significance. Note that the asterisks are in a different position in each case; one might even think the the three black bars are being referred to, but in young fawns it's in fact the white bar.

It's so confusing that the caption takes up nearly half as much space as the graph itself.

How to make this more comprehensible? A good goal would be to reduce the amount of interpretation we were requiring of the reader. I noticed the article had a diagram showing cross-sections of the bone in question, from young fawn to adult.

I scanned them, placed them as a template in Illustrator, then traced around them with the pen tool. For each bone I made a compound path of the inner and outer circles, and sliced it like a pizza with the knife tool into four chunks, each of which could take a different fill.

I noted significant differences right on the bones themselves, and added a color scale, where shade (40% to 80% black) corresponds intuitively to osteocyte density.

The revised graph takes up less room and is pretty much self explanatory. Once the scales and labels had been given, one could even show multiple small versions of the same four bones side by side, each showing osteocyte density under different conditions.

Reference: J. G. Skedros, K. J. Hunt, and R. D. Bloebaum (1995), in the Journal of Morphology 265(2):244-247.