Regibility and Leadability- A Lecture

Legibility carries different meanings for different constituencies. At a recent lecture entitled “Legi…….” Denis Pelli described his collaboration with typographer __. Several years went by before they realized that the terms they were sharing in their experiments and investigations meant quite different things to each.

In a dry and fairly colorless (no infographics here) chart Pelli attempted to demonstrate that after a certain threshold of ‘readability’ has been reached, the only improvement that a choice of font can be bring to the experience of reading is in how pleasureable the experience is. Not how fast, not how easy but simply how pleasurable. The typography practioners in the audience took exception to this. Somewhere their sense of purpose was threatened by the notion that pleasure was after a certain point, all they were delivering.

One apparent student piped up with a thesis that dyslexia had something to do with the rotational transposition of letterforms such as b d g and h. The professor would have none of this and dismissed the ‘theory’ with loud ruminations on the complexity of dyslexia. Few understood this. The fearless student questioned how dyslexia operates, if at all, in non Roman languages. The audience wondered too, but an answer from the professor was not forthcoming.

Good scientists are expected to perform magic and the professor did not disappoint. A blurry sort of composite letter was projected on the screen. Quite Jasper Johns looking. We were asked to identify the letter, in turn, the people in the front of the auditorium, the middle and the back. Each saw a different letter- e or c or o. A smaller version of the same composite letter was flashed on screen and the questions repeated. B, D M. Another even smaller version drove the point home. Typographers already ‘ know’ that scaling affects the ability to identify different letterforms to different degrees. But no-one had seen such a dramatic proof and this was the requisite bit of magic.

When reading the eye makes 4 eye movements, glimpses, a second and this is fairly stable across all readers. What does vary is visual span and this measures how far either side from a central point in a group of letters someone can read. Reading speed is the product of rate of glimpses and visual span. Speed is constant across most fonts and Cleartype had no effect on reading speed.

First experiments I did with type were to photograph a page of text, take the negative and in the dark room blur the page around the point where it starts to become illegible.

Theres a difference between looking at something far away that you know you will understand when you get close to it. And looking at something from far away that you know you won’t understand when you get closer.

Category: Art, Design, Language


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