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Tools and concepts for effectively displaying information in two dimensions

Author: Edward Tufte. (1990)

Abstract: Tufte discusses the concept of flatland (2-dimensions) and the task of escaping flatland as the key aim of envisioning information. This book looks at a range of tools for effectively 'escaping'.

Tufte talks about the concept of flatland - when information from the real world is transferred to a two-dimensional media such as paper or a computer screen.

Escaping flatland is the essential task of envisioning information - 'for all the interesting worlds that we seek to understand are inevitably and happily multivariate in nature. (p12)

An example of orreries - early mechanical simulations of the solar system - that committed a grave sin in information design of directing attention to the display method rather than the communication - in this case the planetary motion. (p16)

Focus on three-dimentionality of a diagram over information. But is not the information more important that the experience. This is an interesting argument - Norman argues that the experience is more important than usability, and that users will put up with bad usability if the total experience is great.

An example of a Javanese railroad timetable (1937) using diagonals moving across a 2-D grid. (p24) It puts each train into context by displaying its journey visually relative to another. Although complex, it is easer to cognate this context - to mentally map it ie speed, crossing, frequency. Each journey line is multifunctional (p26) so it holds much more information. Why is this so effective, and how does it give so much information in such an apparently simple way? I think the key is what Tufte describes as micro-macro information display, where a user can use small amounts of information alone, or in a larger context with other information.

Another example is changing dimensional viewpoint - in this case a Japanese weather map displays temperature information from a horizon line viewpoint rather than an aerial viewpoint (to show temperature variation across the land mass.

Yet another is the famous courtroom graphic used in the John Gotti trial displaying a matrix of criminal information about prosecution witnesses in a bid to discredit their testimony. The graphic was considered a principle cause for acquittal (New York Times, March 14, 1987). Says Tufte: "Unlike speech, visual displays are simultaneously a wideband and a perceiver-controllable channel. Visual info encourages a diversity of individual viewer styles, and rates of editing, personalising, reasoning and understanding (p30).

Average and variation of average are 2 fundamental summary measures of statistical data. (p32)
By focus on data, rather than data containers (table grids, for example), design strategies are transparent and self-effacing in character - designs so good they are invisible. To many data presentations seek to attract and divert attention by means of display apparatus. The data should speak for itself (p33). Tufte talks of the concept of chart junk, or cosmetic decoration. Does this mean that the role of communicating by creating focus is frowned upon? Need to look at research on perception - particularly selective perception.

Clutter and confusion are failures of design, not attributes of information. Simpleness is another aesthetic preference, not a guide to clarity. It is a false equation that simpleness of data and design = clarity of reading. (p51)

The point is to find design strategies that reveal detail and complexity, rather than to fault the data for an excess of complication. Or worse, to fault the viewer for lack of understanding. This view correlates to that of Norman on the responsibility for knowledge transfer.

Micro and macro design - the concept of looking for hierarchies in large data fields.

Layering and separation - a key tool to designing information. Different information hierarchies are represented through differences in design values - ie colour, texture, shape, tone, typography.

The 1+1=3 principle - another key in information design. (p61) Noise ads to this principle, creating clutter (dark on light, for instance, creating vibration and confusion).
Small multiples (p67) can be used to reveal a range of options. Comparisons must be enforced within the range of the eyespan.

Colour (p81) is fundamental in information design - uses are to label, to measure, to represent or imitate reality or to enliven or decorate. Suggests taking pallets of colours from nature, and identifies the problem of perceived colour shifts in different contexts.