I have for some time tried to put my phone in silent mode and turn off my e-mail program before lunch. I am most productive in the mornings, and being able to work 3-4 hours without any interruptions, is very valuable.
My solution to the problem of minor (and larger) interruptions has come out of a need of getting more concentrated time to focus on working in the lab, programming, writing papers, etc. It is very difficult to keep focus when new e-mails are popping up all the time. One thing is the interruption time, another thing is the recovery time. In the paper Understanding Email Interaction Increases Organizational Productivity, Jackson et al. show that the recovery time after an e-mail interruption is a little more than a minute, on average. This is based on detailed analyses of a group of people over several working days. They conclude:
All would see a new email-arrived icon appear in the system tray when new email arrived, and 57% would also see a new email-arrived pop-up dialogue box appear. It took each of them an average of 1 minute 44 seconds to react to a new email notification by activating the email application — 70% within six seconds of their arrival and 85% within two minutes of arrival. We found the time it took them to recover from email interrupts and return to their work at the same work rate at which they left it was on average 64 seconds.
An earlier study by DeMarco and Lister (Peopleware: Productive Projects and Teams), show that for phone calls it is much worse: the average recovery time is 15 minutes on average.
Even though these studies are a few years old, I don’t think we have been any better at multitasking in the last years. It may even be worse, with the other types of time-consuming things that we engage in (Twitter, Facebook, etc.). So in the future I will work even harder to minimize interruption time and the recovery time.