Data Visualization (1)

Posted on March 12th, 2012 by Jamie Mahoney

As a vast part of this project is based around the presentation and visualization of the data, I’ve started reading around the ‘art’ of visualizing information in order to ground my choices in accepted theories and principles. As I’ll be consulting a number of sources, I’ll be blogging about data visualization over multiple posts. This first post is based around me reading Edward Tufte’s ‘Envisioning Information’

The book itself covers a wide range of areas and gives a lot of examples of how the principles it discusses have (or haven’t) been applied over the course of history, from Galileo to the current day. If you’re interested in the visualization of information, then the book is definitely worth reading, but I have taken a few quotes from the book that strike me as being particularly pertinent when it comes to my work on this particular project.

A grave sin of information design – Pridefully Obvious Presentation. Presenting in such a way that the focus is on the method of presentation, rather than the information being presented.

These two sentences struck me as being very important when it comes to presenting information, especially ing software / web design. When using new and interesting libraries and code bases, it becomes very easy to get trapped in the ‘excitement’ of all the new ways you *could* present the information. If the purpose of the project is, as in this case, to present information in such a way that it is useful and informative to the user of the system or service, then the focus has to be on the best way to present the information to the user, not the best way to show off how you *could* present the information to the user.

…promoters imagine that numbers and details are boring, dull and tedious, requiring ornament to enliven. Cosmetic decoration, which frequently distorts the data, will never salvage an underlying lack of data. If the numbers are boring, you’ve got the wrong numbers.

It is often tempting to ‘decorate’ a presentation of information, in order to increase how visually appealing the visualization is. Here Tufte makes a point that cosmetically decorating a visualization can often lead to a distortion of the data. If there’s not enough meaningful data there, then making the visualization look pretty will do nothing to increase how useful the visualization is. Further to this, if the embellishing is being done because the data itself is boring, then what is the point in visualizing it? The data being presented must, by definition of being useful, be interesting and of relevance to the ‘users’ (for want of a better word) that will be viewing the visualization.

Worse is contempt for our audience, designing as if readers were obtuse and uncaring. In fact, consumers of graphics are often more intelligent about the information at hand than those who fabricate the data decoration.

…no matter what, the operating moral premise of information design should be that our readers are alert and caring.  They may be busy, eager to get on with it, but they are not stupid.

Visualizations of data sets should be done with a target audience in mind. If someone is interested in the data, then the chances are that they have a reasonably sound base of knowledge surrounding the concept the data deals with. As such, they shouldn’t be treated as though they are 2 years old and need even the most basic of concepts explaining to them.

What E.B White said of writing is equally true for information design: “No one can write decently who is distrustful of the reader’s intelligence, or whose attitude is patronizing”

Again, this relates back to understanding your target audience. If you don’t understand the audience, you can’t target the visualizations at them and present the data in a useful and meaningful way.

Display of closely-read data surely requires the skilled craft of good graphic and poster design: typography, object representation, layout, color, production techniques and visual principles that inform criticism and revision. Too often those skills are accompanied by the ideology of chartjunk and data posterization; excellence in presenting information requires mastering the craft and spurning the ideology.

This point refers back to one made earlier regarding the over embellishment of visualizations, there are many areas within information visualization that require the graphic/design elements to be considered, such as layout, colour choices or how the data is represented. This is (more or less) with the graphic design process should stop, there’s no need to embellish the presentation of the visualization itself, attaching superflous images around the periphery does nothing to improve the visualization of information and only serves to distract the viewer.

To clarify, add detail.

This point is really simple and yet very important and useful, if a point needs clarifying, add more detail to the visualization. Simple.

Visual displays rich with data are not only an appropriate and proper complement to human capabilities, but also such designs are frequently optimal. If the visual task is contrast, comparison and choice – as so often it is, then the more relevant information within eyespan, the better. Vacant, low-density displays, the dreaded posterization of data spread over pages and pages, requires the viewers to rely on visual memory – a weak skill, to make a contrast, a comparison, a choice.

The human brain can process quite a lot of information when shown it, but visual memory is generally weak; this should be remembered when deciding how to present information to the user – show them what you can on one screen, don’t make them remember details as they move from screen to screen to screen – they’ll forget!

These are just a few of the many points made in Tufte’s book, but they all apply in one way or another to this particular project. As I read more around data visualization I’ll be writing more blog posts on the subject.

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3 Responses to “Data Visualization (1)”

  1. [...] principle is similar to a concept I’ve blogged about from one of Tufte’s books. The information being presented to the audience needs to be easily [...]

  2. Isabel Virgo says:

    Hi Jamie. Thanks for this thoughtful post, I really agree that readers are too often patronised and feel put off by badly presented information. Requested Tufte’s book from our library!
    What kind of visualisations have you been doing?
    As the course data project assistant at the University of Sheffield I’ve been mapping processes and schedules for presentation to professional services staff. I’ve just written a post about the challenges this has presented so far: http://scribe.jiscinvolve.org/wp/2012/03/13/modelling-course-data-schedules-and-deadlines/

    • Thanks for your comment Isabel, I think we met at the Course Data programme meeting in Leeds? I remember the spiral!

      At the moment I haven’t done any real visualizing as such, I’ve primarily been working on constructing a valid dummy data set of course and related data while we wait on a new system being implemented at the university. Now that I’ve done that, I’m starting to look at visualizations and services that we can create using the data that is being produced, to improve the student experience. If all goes to plan there should be some tangible outputs over the next few weeks.

      In terms of Tufte’s books, I’ve started a new blog post based on another of his books, which I’ll be posting over the next day or so. They’re definitely worth a read though!