• Strategy
  • CFO Magazine

Tangled Up in Tasks

Multitasking and frequent interruptions are inescapable aspects of office life, but they can exact a toll.

The estimate is startling. Naturally, upon reading it, I have to leave my office and tell a colleague about it.

According to Basex Inc., a knowledge-management research firm, work interruptions cost the U.S. economy at least $650 billion a year. Analysts Jonathan B. Spira and David M. Goldes reckon that 28 percent of the typical knowledge worker’s day, or 2.1 hours, is consumed by unnecessary interruptions and recovery time. Their calculations are based on surveys and interviews conducted over the past three years.

Surely, skepticism is appropriate regarding such a staggering sum (amounting to 5 percent of the gross domestic product). Still, there is justified concern over what researchers call “work fragmentation,” associated with interruptions and multitasking. The technologies that connect us and enable us to do our jobs — E-mail and instant messaging, cell phones and PDAs — can also diminish our productivity, as recent research demonstrates.

For example, in a 2005 study, researchers at the University of California at Irvine found that information workers at an outsourcing company spent an average of 11 minutes on a project or task before they were interrupted. Once diverted, it took them 25 minutes to return to the original task. Spira and Goldes cite a British researcher who administered IQ tests to different groups of people; the group that was distracted by E-mail and ringing telephones scored an average of 10 points less than a control group (and 6 points less than a group in another study that smoked marijuana before taking the test).

Some observers suggest that multitasking and interruptions can almost drive us, well, nuts. Edward M. Hallowell, M.D., a well-known expert on attention deficit disorder (ADD), says he increasingly sees people who exhibit symptoms of what he calls ADT, or “attention deficit trait.” Chronically overbusy and disorganized, “they have what I call a severe case of modern life,” says Hallowell, a child and adult psychiatrist in Sudbury, Massachusetts.

An Inverted U

Of course, multitasking can be a boon as well as a bane. According to a 2006 study by researchers at MIT, it can lead to higher productivity. Sinan Aral, Erik Brynjolfsson, and Marshall Van Alstyne studied workers at an executive-recruiting firm, reviewing data on more than 1,300 projects over a five-year period and monitoring more than 125,000 E-mail messages for 10 months. They found that workers’ revenues were “a function not only of how fast they work, but also of how much they multitask.” Heavier multitaskers were able to complete more projects than others, even though their speed per project may have been slower.

But the MIT researchers also found that the relationship between multitasking and productivity is shaped like an inverted U. More multitasking means more output only up to a point, “after which there are diminishing marginal returns, then negative returns to increased multitasking.” They noted that previous research has shown that multitasking is associated with “cognitive switching costs,” which means that as tasks pile up, efficiency drops and errors multiply.


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