When University of California, Irvine researcher Gloria Mark studied modern office workers, she uncovered something interesting about how often we switch tasks at the office: knowledge workers switch work events as often as every three minutes.

Now, the ability to switch from one task to another is vital when you’re getting things done, but task interruptions, which are a form of task switching, are costly to productivity. 

Gloria Mark’s study shows that 40% of task switches are in fact work interruptions. She also shows that once focus is broken, it can take as long as 25 minutes to return to the original task. 

But while there is a misconception that work interruptions usually come from outside, there are actually two types of interruptions that rob us of our productivity: self-interruptions and external interruptions.

Let's break down each of them, and figure out how to reduce them.


Self-interruptions happen when you abandon an ongoing task before you finish it, in order to direct your attention to a different task, without being prompted by an external event or another person. 

Imagine you’re working on a spreadsheet. You remember that you haven’t had coffee this morning and you’re feeling kind of sluggish. As you get coffee, you realize that you forgot to mention something to your colleague. So you stop by her desk, and chat for a few minutes. Then you sit at your desk and before you go back to your spreadsheet, you notice that you have an email from your boss sitting in your inbox, and decide to reply now. Since you’re doing email, might as well take care of the other three new messages awaiting you. Eventually, you go back to your spreadsheet, but you have to take a few minutes to remember what you were doing there and why. 

All of these interruptions are prompted by you remembering or thinking about something that you need to do. As Gloria Mark puts it, “self-interruption occurs as a function of prospective memory events.” 

Self-interruptions can sometimes be much-needed and well-deserved mental breaks after a burst of productive work. This implies that you are aware and deliberate about your self-interruptions - easier said than done. Beware though of long stretches of self-interruptions that end up biting out a big chunk of your work day - those are the real enemy! 

Surprisingly, we seem to distract ourselves more when we’re surrounded by others, and not when we’re alone. Gloria Mark’s research found that open office concepts (cubicle vs. enclosed office), were associated with a 64% increase in self-interruption

It’s also interesting that we tend to interrupt ourselves more often the earlier it is in the day. As the day progresses, self-interruptions seem to taper off. This might be either because afternoons are when most people get into the flow of things, or because we feel a pressure to complete certain tasks before the end of the day. 

Solutions for self-interruptions

Being aware that we get in our own way when it comes to getting things done is the first step in stopping self-interruptions. Self-awareness is vital if you are to improve your ability to concentrate. 

Here are a few tools and ideas to try to reduce self interruptions:

  • StayFocusd is a Chrome extension that you can set to block certain websites and limit the total time you spend on them.
  • Rescue Time is a monitoring tool that tells you how you’re spending time on your computer. Use it to learn about how you spend your time working on your computer and where you need to make changes.
  • Plan your interruptions in advance. Write down an “if…then” statement to use when you lose focus. For example, “if I get mentally tired working on this task, then I will clean up my email for 10 minutes/browse Facebook for 5 minutes/etc.”
  • Music and background noise can help you get into a the state of flow. There’s a reason so many people prefer to work in coffee shops! Experiment with incorporating some of these audio tools into your workday routine.
  • The Pomodoro technique is a personal time focus strategy that schedules bursts of productivity with short periods allowed for distractions.

External interruptions

External interruptions are those interruptions that are outside of your control - for example, the phone rings, your team member stops by your desk, or your group chat notification pops on your screen. 

So why do external interruptions matter? For one, they are actually a good predictor of future self-interruptions. According to Gloria Mark’s research, each external interruption in the previous hour increased self-interruption by 8% in the following hour. It seems that when we are interrupted by external factors, we are more likely to remember or think about other tasks than the one at hand. 

This suggests that we can get into a habit of self-interruptions after an external interruption, which can wreak havoc on our productivity.

The good news though is that tasks interrupted by external factors take less time to resume than self-interrupted tasks. But it’s still preferable to try to get rid of external interruptions altogether. 

Solutions for external interruptions

Even though there are some strategies that can diminish external interruptions, you need to remember that you can’t control them fully. Make your peace with that thought, but it still doesn’t hurt to give these strategies a try.  

  • Have a signal with your team members that means “do not disturb.” It might be wearing headphones, setting your IM status to DND, or even sending out a broadcast message to your team members that you need a couple of quiet hours. Whatever it is, make sure everyone on the team knows what it means, and is willing to respect it.
  • Do yourself a favour and turn off notifications (email/chat/apps) - this will stop external distractions from even showing up, and you can take the time to review them during a break from your task.
  • Schedule a work from home day. Try this when you want to completely eliminate in-person office interruptions. This is a drastic but highly effective way to block out external distractions - if you are good at managing other kinds of interruptions at home.
  • Choose a quiet work day (or at least a half of a day) and honour it along with your team. Tuesday morning might be a great idea, since it seems to be the time most people are at the peak of their productivity for the week.

How do you manage and work with internal and external interruptions? What sort of strategies work for you? We’d love to hear from you in the comment section below!