Every time you switch from one task to another, from writing to a message and back, you pay a price: time to drop one set of details, time to load the next, and a stretch afterwards when part of your mind is still on the last thing. Each switch costs only minutes. Across a day of notifications, they can add up to hours.
What the research found
Getting back takes about 23 minutes
Gloria Mark, a professor of informatics at the University of California, Irvine, spent years observing people at work. In one study her team found that interrupted tasks were resumed after about 23 minutes on average, and that people typically worked on two other things before getting back. Interruptions also left people working faster, but with more stress and frustration.
Part of your attention stays behind
Sophie Leroy, now at the University of Washington, showed in 2009 that when people switch away from an unfinished task, their thoughts keep returning to it, and they do worse on the next task as a result. She called it attention residue. It's the reason a quick look at email before a meeting can leave you distracted through the meeting.
Switching itself is slow
In lab experiments, Joshua Rubinstein, David Meyer and Jeffrey Evans (2001) found that people lost time at every switch between tasks, and that the cost grew with the complexity of the tasks. Meyer has suggested that heavy switching can cost a large share of a person's productive time. What feels like multitasking is mostly fast switching, with a small cost each time.
How it adds up
Take a modest case: six interruptions a day, and 15 minutes to get properly back into the work after each. That's 1h 30m a day, or about 345 hours over a working year. Try your own numbers in the context switching calculator.
Seven ways to switch less
- Batch communication. Check email and chat at set times, two to four a day. A study by Kostadin Kushlev and Elizabeth Dunn found people who checked email three times a day felt less stressed than those who checked whenever they liked.
- Turn off notifications during focus blocks, on the computer and the phone.
- Work on one task per session. A Pomodoro or a deep work block is for one thing.
- Finish a natural chunk before switching, and leave a note on where you were, so getting back in takes seconds rather than minutes.
- Group similar work. All the calls together, all the reviews together.
- Protect blocks from meetings. A meeting is the most expensive interruption of all; the meeting cost calculator shows why.
- Agree on response times with your team. If everyone knows a message can wait an hour, nobody has to watch the chat.
The plane effect
One reason people get so much done on flights is that the interruptions simply stop: no messages, no meetings, nobody at the door. Flight borrows the idea: your focus session is a real flight, and the whole point is to stay on board until you land.