When you have all your data in order, you’re ready to visualize. Whatever you’re making, whether it is for a report, an infographic online, or a piece of data art, you should follow a few basic rules. There’s wiggle room with all of them, and you should think of what follows as more of a framework than a hard set of rules, but this is a good place to start if you are just getting into data graphics.
The design of every graph follows a familiar flow. You get the data; you encode the data with circles, bars, and colors; and then you let others read it. The readers have to decode your encodings at this point. What do these circles, bars, and colors represent?
William Cleveland and Robert McGill have written about encodings in detail. Some encodings work better than others. But it won’t matter what you choose if readers don’t know what the encodings represent in the first place. If they can’t decode, the time you spend designing your graphic is a waste.
See Cleveland and McGill’s paper on Graphical Perception and Graphical Methods for Analyzing Data for more on how people encode shapes and colors.
You sometimes see this lack of context with graphics that are somewhere in between data art and infographic. You definitely see it a lot with data art. A label or legend can completely mess up the vibe of a piece of work, but at the least, you can include some information in a short description paragraph. It helps others appreciate your efforts.
Other times ...