In the past decade, studies have shown that IT leads to increased corporate productivity, but until recently, no one had measured how it affects work at the individual desktop level.

Marshall Van Alstyne and co- authors Sinan Aral and Erik Brynjolfsson recently completed a five-year study analysing 1,300 projects and 125,000 e-mails to see how IT affects individual productivity. (The National Science Foundation, Cisco Systems and Intel sponsored their work.) In December, their research won the award for best paper at the International Conference on Information Systems, the largest academic IT conference in the world. Van Alstyne talked with Kathleen Melymuka about the authors' initial findings.

What did your study cover?

We looked at white-collar workers -- executive recruiters. We wrote software to track e-mail communications over a year, and we tracked five years' worth of project activity. We chose extremely measurable output: dollars generated, contracts executed, start and stop dates of projects. These were highly representative of task-based work in sales accounting, consulting, law -- all kinds of things. We interviewed and surveyed employees as well. It was voluntary, but better than 85% participated in the study. Then, at the individual and team levels, we ran analyses and figured out which variables are the best explainers of productivity. What technologies did you look at?

We asked employees how they were spending their time and where they were getting the greatest value: internal databases, external databases, other technologies, phone, face to face.

And you found a correlation between IT use and productivity?

Absolutely yes, though not always as we had expected. If you look across e-mail and social networks, database and phone, the surprise was that overall, IT use is not associated with an increase in speed. In fact, it's associated with slower speed. But we found that heavier IT users are much heavier multitaskers, so over time, they're completing more projects and bringing in more money for the firm.

How does that work?

Heavier IT users are taking on more work. This slows down the work they're already doing, but because they're doing so much more, they're more productive. So simply looking at speed, they might at first appear to be slower, but since they're multitaskers, they're more productive overall. The lower IT users are doing tasks serially, but high IT users are doing tasks in parallel.

Can you hit a wall while multitasking?

The relationship between multitasking and productivity is an inverted U shape. Up to some point, productivity increases with multitasking, but past that point, multitasking detracts from productivity. Heavy IT users have more capacity for multitasking, so we'd say polish your IT skills but know your limits.