Check out this psychology experiment that was designed to measure the cost of your distractions:
When you sit at your computer trying to write or work, there is a real danger that you will get interrupted by an email, instant message, text message, or phone call. Even if you do your best to skip past the distractions, there still may be a moment where you have to stop and decide whether to answer the phone or check your email—and that itself is a distraction..
What influence do all those small interruptions have on your ability to perform complex tasks?
This question was addressed in a clever set of studies by Erik Altmann, Greg Trafton, and David Hambrick, described in a paper in the February 2014 issue of the Journal of Experimental Psychology: General.
To explore the question, the researchers had to develop a complex task that would allow them to observe errors. Participants saw a computer screen with a box in the center. In each trial, there was a number and a letter. One of the characters was inside the box, the other outside. One character was either in italics or underlined. One was either red or yellow. The character outside the box was either above or below it.