September 03, 2004

Bouma

Kevin Larson has posted a nice historical survey of "the last 20 years of work in cognitive psychology" on "word recognition" -- the recognition of printed English words, that is -- from the particular perspective of a "reading psychologist" speaking to the Association Typographique Internationale.

He got himself into this situation by taking a job at Microsoft, and winding up on the ClearType team, where he discovered that "the team believed that we recognized words by looking at the outline that goes around a whole word, while I believed that we recognize individual letters". Apparently many people involved in typography believe that the outline around words is important, and call this outline a bouma, named after H. Bouma, the author of a 1973 paper "Visual Interference in the Parafoveal Recognition of Initial and Final Letters of Words" ( Vision Research, 13, 762-782).

Larson explains that "[i]n my young career as a reading psychologist I had never encountered a model of reading that used word shape as perceptual units, and knew of no psychologists who were working on such a model. But it turns out that the model had a very long history that I was unfamiliar with." His paper is an attempt "to review the history of why psychologists moved from a word shape model of word recognition to a letter recognition model, and to help others to come to the same conclusion".

It looks to me like he's right, both about the widespread Bouma-culture among typographers, and its lack of scientific support relative to alternative theories. Specifically, he argues that all of the results that have been taken to support word-shape models "make more sense with the parallel letter recognition model of reading than the word shape model".

It's common for discredited scientific theories to live on -- sometimes for hundreds of years -- in applied areas. Read Ray Girvan's weblog for an entertaining parade of examples. But unless I'm just being parochial, this kind of thing is more common in language-related fields than elsewhere.

[tip via email from Kerim Friedman]

 

Posted by Mark Liberman at September 3, 2004 07:15 AM