Someone (possibly Liz) pointed out a study on multitasking in the classroom at last week's CSCW. Pointed out, of course, while we were hanging out in the backchannel. The Laptop and the Lecture: The Effects of Multitasking in Learning Environments (pdf) by Hembrooke and Gay from Cornell's Human Computer Interaction Lab, published in the Fall 2003, Journal of Computing in Higher Education. (Abstract in the extended entry)
The authors reference a wide body of literature that shows people have difficulty processing two tasks at once: things like listening for a specific number string while being shown new vocabulary. And this study essentially reinforces what has been learned before, that people can generally only devote attention to one thing at a time. The group with classroom access performed more poorly on a end-of-class quiz than did the group without.
However, as mentioned in the abstract, they delve into the different styles of use and turned up a surprising item. The students who appear to be browsing outside of class-specific topics ("browsers") tended to do better than those who sought topic-specific information ("seekers"). This suggests to me that the browsers are either not paying direct attention to their browsing, or that the seekers get too deep into the on-topic information and miss classroom dialog. And the authors suggest as much in their summary: "The sustained distraction, regardless of content relevance appears to be the nemesis of the multitasker; if one is adroit at staccato-like browsing, processing multiple inputs simultaneously may not suffer to the same extent."
I would love to see the follow-up to this look in more detail at the type of backchannel activities. If a lecture is set up around making use of the backchannel, I would suspect students without access to that channel would miss out on some potentially-useful information during class.
From my perspective of the CSCW conference, I was certainly doing a bit of multitasking, but the backchannel provided context and information that I would have never discovered with just pen and paper. And the immediacy of the backchannel was infinitely better than jotting down a "look this up" note for myself. In some cases I would never have thought to jot the note in the first place.
The abstract tells us most of the story:
The effects of multitasking in the classroom were investigated in students in an upper level Communications course. Two groups of students heard the same exact lecture and tested immediately following the lecture. One group of students was allowed to use their laptops to engage in browsing, search, and/or social computing behaviors during the lecture. Students in the second condition were asked to keep their laptops closed for the duration of the lecture. Students in the open laptop condition suffered decrements on traditional measures of memory for lecture content. A second experiment replicated the results of the first. Data were further analyzed by "browsing style." Results are discussed from Lang's Limited Process Capacity model in an attempt to better understand the mechanisms involved in the decrement.