Worker, Interrupted: The Cost of Task Switching
BY: KERMIT PATTISON
How often is the modern office worker interrupted?
We had observers go into the workplace and we timed people's activities to the second. We've been to various workplaces, all high-tech companies. We wanted to look at information workers. We had observers shadow each person for three and a half days each and timed every activity to the second. If they pick up a phone call, that's the start time. When they put the phone down, that's the stop time. When they turn to the Word application we get the start time and stop time. We found people switched these activities on average of every three minutes and five seconds.
Roughly half of them are self-interruptions. That's to me an endless source of fascination: why do people self-interrupt? I do that all the time.
When is interruption beneficial?
If an interruption matches the topic of the current task at hand, then it's beneficial. If you're working on task A and somebody comes in and interrupts you about exactly that task people report that's very positive and helps them think about task A.
There's been a lot of research into the psychology of problem solving that says if you let problems incubate, sometimes it helps in solving them. A good example would be a software developer who just can't trace a bug so they put it aside and let it incubate. The answer may come back to the software developer later while he or she is working on another task. This is an example of how switching tasks may be beneficial.
If interruptions are short they're usually not so bad. Imagine you're working on this article and some one comes in and says, "Here, can you sign this form?" You sign it, it's a very subordinate kind of task and you go back to doing your work. Any kind of automatic task that doesn't require a lot of thinking would not be a major disruption.
