colleagues think the effect occurs because fonts that are more awkward to read encourage deeper processing of the to-be-learned material.
Diemand-Yauman first tested this principal in the lab with 28 participants (aged 18 to 40) who spent 90 seconds learning the seven features associated with three alien species. Half the students learned from materials written in clear 16-point Arial font, whereas the other half learned from materials written either in 12-point Comic Sans or 12-point Bodoni. As the researchers explained, these last two fonts are obviously more difficult to read when considered side-by-side with the Arial font, but viewed on their own few people would notice anything amiss. Fifteen minutes later the participants were tested and the key finding was that those who learned from the harder-to-read fonts answered 86.5 per cent of questions correctly, compared with the 72.8 per cent success rate achieved by the participants who learned from the clearer font.
For a follow-up study the researchers collaborated with a high school in Ohio. Teachers sent in their work-sheets and power-point slides and the researchers made them more difficult to read. They did this either by switching the fonts to Comic Sans Italicised, Haettenschweiler or Monotype Corsiva, or, if the materials were hand-written, simply by shaking them about in a photo-copier to make them blurry. The history, English and science teachers used the manipulated materials for one of their classes but not the other, which acted as a control. You guessed it, of the 220 participating pupils, those who learned from the harder-to-read materials subsequently performed better in the relevant class assessments than did the pupils who learned from the unadulterated materials (for more statistically minded readers, the effect size was d=.45).
When people find something easy to read, they take that as a sign that they've mastered it. Conversely, the researchers believe harder-to-read fonts provoke a feeling of lack of mastery and encourage deeper processing. However, there's obviously a balance to be struck. If material becomes too difficult to read, some students may simply give up. Another possible mechanism is that the less legible fonts are somehow more distinctive, rendering them more memorable. Diemand-Yauman's team doubt this explanation because distinctiveness should wear off over time, and anyway they didn't use any fonts that pupils wouldn't have seen before.
The researchers think their finding could be the tip of the ice-berg as regards using cognitive findings to boost educational practice. 'If a simple change of font can significantly increase student performance, one can only imagine the number of beneficial cognitive interventions waiting to be discovered,' they said. 'Fluency demonstrates how small interventions have the potential to make big improvements in the performance of our students and education system as a whole.'
Diemand-Yauman, C., Oppenheimer, D., and Vaughan, E. (2011). Fortune favors the Bold (and the Italicized): Effects of disfluency on educational outcomes. Cognition, 118 (1), 111-115 DOI: 10.1016/j.cognition.2010.09.012