We all know this and have heard it hundreds of times. To work efficiently we have to single task. No multitasking. See the reason why.
http://blog.bufferapp.com/what-multitasking-does-to-our-brains#more-5202
DawsonITE is a blog devoted to Educational Technology. It's compiled by Rafael Scapin, Coordinator of Educational Technology at Dawson College in Montreal (Canada).