On Monday, I attended a course taught by Edward Tufte on Presenting Data and Information. I’ve flirted with Tufte’s ideas before, and Tufte fans may recognize some of them from Designing for Flex part 5 – Designing content displays. This is the first time I’ve heard a summary of Tufte’s work from the man himself, however, so I uncovered some ideas that build on Part 5 and offer some additional guidance.
- Content first – Especially for information structures, users care about the information itself, their content. Avoid obscuring information with application chrome, navigation controls, and decorative design. This shouldn’t be new to anyone who has read Part 5.
- Design dense content displays – Tufte argues that information overload is a failure of design, not an artifact of presenting too much information. He points out that the human brain receives an enormous quantity of information every second through the senses and has absolutely no problem interpreting it. If your information is confusing, its because you are presenting it in a way that doesn’t make sense to your viewers and you should fix your design. I’d add, however, that designing very high density content displays is difficult to do and its easy to wind up with a confusing clutter if you are not a skilled information designer. Incorporate content displays with three or four variables and see if you can integrate more without confusing someone who has never seen your display before.
- Nothing can be erased without erasing information – Good information designs have few elements that are irrelevant to the information itself. Whether these elements are needless graphical decorations or irrelevant controls or application chrome such as panel borders, all stand in the way of the user understanding his information. The test to apply is: if you can erase any page element without erasing actual content, do so. Obviously for RIAs and other computer displays this isn’t always possible; some amount of navigation cruft is necessary. But it must be kept to a minimum and away from the content, which should consume the vast bulk of the screen.
- Avoid “relentless sequentialtiy” – Relentless sequentiality is Tufte’s term for information that is segregated onto different screens in a stack, preventing the user from making comparisons by seeing the information all on the same screen. Tufte uses this term to slam Powerpoint, but it can also be applied to many application interfaces that segregate related information into different screens or views. Note that designing content displays to support comparison is covered in Part 5 of D4F.
- Direct reading – Many information displays spatially move information away from the content it is related to. For example, arrows in diagrams are not labeled or are labeled only in legends. Icons are used instead of text. Figures are referred to by number instead of being included directly inline. Footnotes or (shudder) endnotes are used instead of sidenotes in the margin, which are much easier to follow. Avoid these practices. Include additional information right next to the content it elaborates on, using techniques such as callouts or overlays.
- Don’t segregate information by type – for technical reasons or (even worse) simple force of habit, many applications separate different types of information (text, pictures, video, etc) into different screens or sections. Don’t do this. Data type doesn’t matter to users – include all information relevant to a given topic in one section, regardless of what file format it is in or what department in your organization created it.
- Design for the viewer’s fundamental cognitive task – I believe that what Tufte calls the user’s “fundamental cognitive task” is what I call a “goal” in Part 2 of D4F. Regardless of what you call them, your users’ goals should guide the design of your content displays and your application as a whole.
- Problem, relevance, and solution – When producing presentations, Tufte urges you to consider three things: what is the problem we propose to solve? Why is that problem relevant? And finally, what is your solution to the problem? These are also good questions to ask when designing content displays and other application elements such as error messages. It may help to rephrase the questions as “What question does the user have? Why is this information relevant to their question? How will this information help them answer their question?”
- Everything is information – Tufte doesn’t say this explicitly, but I believe it’s important to point out that information design runs throughout your application, regardless of your organizing structures. Every pixel on your screens communicates something, or fails to. Many people seem to believe that information design is only relevant to charting components or dashboards, but this simply isn’t true. The principles behind designing dense yet clear displays of information should guide every design decision for every screen your application has, from content displays to forms to dialog boxes.