Interlibrary loan has reclaimed my copy of Visualization Analysis and Design, so I’m on to the next book on my shelf: Information Visualization: Perception for Design by Colin Ware.
I stand behind Ware’s position that data visualization is a tool for cognitive work, an external aid that shores up memory and pattern perception. Our brains need tools to think through complicated information, the same way our hands need tools to weave cloth. I can see the numbers in a spreadsheet, but interpreting them is like trying turn a pile of yarn into fabric with nothing but my fingers. A simple tool like a crochet hook radically extends what I can do with raw materials.
I do, however, struggle with the profit model introduced in the first chapter. Ware writes that learning to interpret new graphic symbols comes with a cost, and that novel designs should be used only when their benefits outweigh the cost of learning to use them.
I struggle with this because I want to make weird stuff and stick numbers in it. However, this is not a well-considered design philosophy! A useful question might be, “am I making this for the joy of making something, or am I making this to facilitate cognitive work?” Making weird stuff is one of life’s purest joys and I highly recommend the experience, but it may or may not create a user-oriented tool. If I’m trying to facilitate cognitive work, what kind? The cognitive work might be reflection or an emotional experience. Or I might be aiming for standard visualization tasks like search, analysis, and transformation. However, it’s best to be clear about my goals early in a project, and make life easy for my audience where I can. If my audience has used crochet hooks all their lives, I shouldn’t hand them knitting needles unless they need to make socks.
Ware frames his discussion of user effort with the distinction between sensory and arbitrary symbols. A sensory symbol is understandable simply because we perceive it, like a photograph or line drawing. An arbitrary symbol has to be learned to be interpreted, like written language or a regression line. It’s easy to forget an unfamiliar symbol’s initial meaning and attach a different meaning later on. However, if an arbitrary symbol is overlearned through practice and repeated use, reinterpreting that symbol is very difficult. The letter A is always going to look like the letter A to someone who reads and writes the Latin alphabet. A bar graph is always going to look like quantities associated with categories to someone who spends a lot of time around visualizations. The effort that it takes to interpret a visualization depends on whether the graphic form is familiar to the audience and, if it is familiar, whether the information being conveyed matches the conventions of the form.
The start of Information Visualization has given me three framing questions for the start of a visualization project:
- What kind of work am I trying to facilitate?
- Does my audience already expect to see this information in a particular way? What is the benefit of showing it in a different way?
- Is the novel way I want to communicate this information the standard way to communicate a different kind of information? Is the novel form valuable enough to justify the work required to re-interpret a conventional form?
This is only a small subsection of the information in the book, but I’m saving visual perception, affordances, and all the rest until I can dig into the details in later chapters. Until next time, may your novel forms be valuable and your overlearning be convenient!