I really enjoyed The Visual Display of Quantitative Information by Edward Tufte. One sentence from the book is all you need as a synopsis:

Graphical excellence requires telling the truth about the data.

The book is a collection of principles that guide how to effectively tell the truth about data. A couple of my favourites even have measurable metrics, like the ‘lie factor’ - a way of checking if representations of numbers in the graphic are proportional to measured quantities.

Hand drawn formula for the lie factor = size of effect show in graphic / size of effect in data.

If the lie factor is greater than 1.05 or less than 0.95, then the graphic is a distorted representation (i.e. a lie).

There are also a number of principles around efficiency and maximising ‘data-ink’, which is the non-erasable core of a graphic. Again, measurable with a little metric, the data-ink ratio is the proportion of a graphic’s ink devoted to the non-redundant display of data information.

Hand drawn formula for the data ink ratio = data-ink / total ink used to print the graphic.

Tufte describes a number of ways for both erasing redundant data-ink and maximising data-ink. It is at this point where the book gets really interesting. He adds a bit of depth by giving the necessary information to critique some of his following redesigns with this quote:

When modern architects righteously abandoned ornament on buildings, they unconsciously designed buildings that were ornament. In promoting space and articulation over symbolism and ornament, they distorted the whole building into a duck. The substituted for the innocent and inexpensive practice of applied decoration on a conventional shed the rather cynical and expensive distortion of program and structure to promote a duck…

Tufte then continues down a road of epic reductionism to maximise the data-ink used in Eleanor Spear’s range bar. Taking the design from this:

Photo of Eleanor Spear's range bar in the book the visual display of quantitative information.

Down to this:

Photo of Edward Tufte's range bar redesign in the book the visual display of quantitative information.

I felt as though Tufte had gone too far, promoting minimalism over legibility, and thus stripping the warmth and welcome from the original design. I guess I’m trying to say that if it is impossible or difficult to gleam understanding from a visual display, then it is nothing more than abstract ornamental art.

But then I realised this was Edward Tufte’s plan all along. He wanted to promote skepticism and critical reactions to his re-designs, as revealed in his Epilogue:

The theory of the visual display of quantitative information consists of principles that generate design options and that guide choices among options. The principles should not be applied rigidly or in a peevish spirit; they are not logically or mathematically certain; and it is better to violate any principle than to place graceless or inelegant marks on paper. Most principles of design should be greeted with some skepticism, for word authority can dominate our vision, and we may come to see only though the lenses of word authority rather than with our own eyes.

Oh, but the best part? That would be the simple word-sized graphics section in the final chapter, which demonstrates simple neat depictions of biomedical data. Stunning. A visual culmination of all the text that precedes it.

The Visual Display of Quantitative Information is available from Amazon. It gets 5 out of 5.

5 stars out of 5.