Spacing of letters, not shape of letters, slightly increases reading speed of those with dyslexia

Arial font was as effective as Dyslexie front when the spacing of letters and words were enlarged. from

In 2008, a new font designed called “Dyslexie” was labelled “a breakthrough” by the media for reportedly being about to help increase the reading speed of those with dyslexia. It received media attention worldwide. Publishers even announced they were going to publish books in the font.

This is despite there being hardly any empirical evidence for the efficacy of Dyslexie.

We conducted a study to see if Dyslexie is indeed more effective than a commonly used sans serif font (Arial) and, if so, whether this can be explained by its special letter design.

Our results found that the benefits of Dyslexie font were pretty small, and that the slight gain to reading speed was actually down to the spacing of the letters and words rather than the specially designed letter shapes.

The design

Dyslexie’s hallmark is its letter shapes. These shapes have heavy bases which are postulated to suppress the supposed tendency of individuals with dyslexia to mirror-reverse or rotate letters. Dutch artist Christian Boer, who designed the font, aimed to make the letters as distinct as possible from each other to avoid confusion between letters.

Disproving the effectiveness of Dyslexie

In our research we tested 39 English speaking low-progress readers from grades 2 to 6. The children were asked to read texts of similar difficulty in Arial and Dyslexie font that had the same letter-display size, but differed in the degree of word and letter spacing.

Our findings show that the Dyslexie font increased reading speed by just 7%. To put this into perspective, in order to match the reading speed of normal readers at least a 70-100% improvement is needed.

Arial gives same results

Importantly, the same gain could be obtained with Arial font when we enlarged the spacing settings.

In most individuals with dyslexia, the cognitive problems that cause their reading impairment are beyond the early visual letter processing level. Many people with dyslexia struggle to learn the rules for sounding out letters. In this case there is no reason to assume that specific letter shapes would assist in making reading easier.

Previous research has also shown that individuals with dyslexia can benefit to a small extent from larger spacing of objects. This is because they struggle more than their normal reading peers to process objects that are presented closely together. In the case of reading, these objects would be words or letters. However, more research is needed to validate this interpretation.

Based on our research and earlier findings, it is clear that typesetting factors like spacing can only marginally contribute to reading improvement in individuals who struggle with reading.

To significantly improve reading it is important to concentrate on remediation of the specific underlying cause(s) of the reading impairment, like training rules for converting print to speech sounds.