As Smith wrote about the advantages to division of labor, the point he was most emphatic about concerning increased efficiency was time between tasks. He contrasted the handyman that fixes a wagon wheel, patches a roof, cleans out the gutters, etc with a worker in a pin factory that hammers pins to a point and then passes them along (he also talks about an individual going through all the steps of creating a batch of pens alone). The point being, that the person with different tasks (and thus interruptions) is far less productive than a person in a society that assigns specific and relatively continuous tasks. Standard of life for the laborer is always the principle argument in favor of the handyman because he is setting his own pace at the expense of his efficiency.

However, in today's society the technologically engendered ADD of being tied to instant communication in a culture that expects instant response in mind crushingly stressful and leads to less productivity. I think that your point about applying filters to communication makes total sense as they have become interruptions. I've noticed personally that as I've spent more time with technology, my attention span has diminished markedly. Most things that I'm involved with nowadays aren't urgently important by nature but people's expectations have changed as to what constitutes timeliness to the degree that I allow myself to be stressed over a couple of hours. Also, I get so many emails in a day that if I don't attack them as they come in, they can be overwhelming.

I need a break from technology