This was a great week on twitter for a RNA-scientist moonlighting as data visualization expert. There are a couple of mantras that I keep on repeating and they all came up this week.
1) In praise of drawings!
A simple drawing is better than a complicated diagram. And these days, it is super simple to draw on the ipad – even unskilled artists can go a long way! Or use whiteboard and include this as a picture in your talk.
This is a wonderful drawing of expansion microscopy by Christophe Leterrrier (@christlet):
2) Avoid 3D!
Unless you are making an interactive web-based animation, 3D is very hard to read and way too often results in confusion or even misleads the reader! Avoid it at all costs. See my recent blog-post on one possible work-around. Here is a recent example that circulated in the RNA-twitterverse by RNAseqblog about usage of RNAseq.
3) Time = line.
If you want to show changes over time, the time almost always goes to the x-axis! A line graph works best if you have many time-points. When dealing with only two time-points like in this case the go-to chart is the slope-chart!
Solution: turn bars into lines, shift 90deg and simplify by using colors strategically and finally, make straightforward labels! PS I hope Dan Graur does not mind me using his graph as an example 🙂 
4) Faceting is always a solution.
If you can’t solve a problematic graph, try faceting aka small multiples aka many little similar graphs. I used it for example here. Faceting is really easy for people using R, but it is, like so many things, also possible in excel. I am not an evangelist for either, both have their value, – it is most important that you try making better graphs regardless of the program you use to create them! Have a look how to do faceting with excel:
helena * jambor 