A few months ago, I wrote a speculative blog post about e-readers. Although I love my Kindle, I worried that these new gadgets made the act of reading a little bit too easy, and that this visual ease might lead, one day, to a shallower engagement with our texts. It was a rather tortured argument, an awkward mash-up of McLuhan and fMRI research.

I'm happy to report that a brand-new paper in Cognition by a team of Princeton psychologists (Connor Diemand-Yauman, Daniel M. Oppenheimer and Erikka B. Vaughan) makes the same point I was trying to make, only much, much better. (They also have, you know, actual evidence.)

Interestingly, they frame the issue in terms of classroom technique, as they take aim at a core assumption of educators:

Many education researchers and practitioners believe that reducing extraneous cognitive load is always beneﬁcial for the learner. In other words, if a student has a relatively easy time learning a new lesson or concept, both the student and instructor are likely to label the session as successful.

That sounds reasonable, right? Shouldn't learning be as easy and effortless as possible? Unfortunately, this assumption turns out to be mostly wrong, as numerous studies have found that making material harder to learn – what the researchers call disfluency – can actually improve long-term learning and retention:

There is strong theoretical justiﬁcation to believe that disﬂuency could lead to improved retention and classroom performance. Disﬂuency has been shown to lead people to process information more deeply, more abstractly, more carefully, and yield better comprehension, all of which are critical to effective learning.

This new paper attempted to provide the most direct test yet of the benefits of disfluency. I'd like to focus on their second experiment, as it involved actual students in actual classrooms in Chesterfield, Ohio. The researchers began by getting supplementary classroom material, such as PowerPoint presentations, handouts and worksheets, from a variety of teachers. (Subjects included English, Physics, U.S. History and Chemistry.) Then, the researchers changed the fonts on all of the materials, transforming the fluent text into a variety of disfluent formats, such Monotype Corsiva, Comic Sans Italicized and Haettenshweiler. Because all of the teachers included in the study taught at least two sections of the same class, the psychologists were able to conduct a neatly controlled experiment. One group of students was given the classroom materials with the disfluent fonts, while the other group was taught with the usual mixture of Helvetica and Arial. The font size remained the same.

After several weeks of instruction, the students were then tested on their retention of the material. In every class except chemistry, the students in the disfluent condition performed significantly better than those in the control-fluent condition.* Here are the scientists:

This study demonstrated that student retention of material across a wide range of subjects (science and humanities classes) and difﬁculty levels (regular, Honors and Advanced Placement) can be signiﬁcantly improved in naturalistic settings by presenting reading material in a format that is slightly harder to read.... The potential for improving educational practices through cognitive interventions is immense. 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. Fluency demonstrates how we have the potential to make big improvements in the performance of our students and education system as a whole.

I'd also like to nominate this paper in the best-paper-title category of 2011: "Fortune favors the Bold (and the italicized): Effects of disﬂuency on educational outcomes."

*If I were a textbook publisher, I'd immediately go out and hire David Carson.