Margen
When you answer messages while working, your brain isn't doing two things at once: it switches between them at full speed. And every jump has a cost — reorienting yourself, remembering where you were — that you pay in time and errors.
Researchers at Stanford University compared people who considered themselves great multitaskers with those who didn't. The result was humbling: chronic multitaskers performed worse at precisely what they prided themselves on — filtering out the irrelevant and switching tasks nimbly.
The practical lesson is simple: group what's similar and do one thing at a time. A full half hour for one task is worth more than two hours pecked at by interruptions.
Source: Stanford University