Good article in Software Developement Magazine on the human cost of context switching. (Requires annoying registration I believe.)

“Gerald Weinberg, in Quality Software Management, Vol. 1, Systems Thinking (Dorset House, 1992), estimates the context-switching cost among three tasks to be 40 percent. That means that 40 percent of your available work time is spent on non-task activities. The rest of the time is split among the three projects. So, if you thought that in a 45-hour week, you could spend 15 hours on each of three tasks, don’t kid yourself. You’re really spending eight hours on project A; eight hours on project B; eight hours on project C; and 24 hours context-switching, figuring out where you were and what you have to do next. The time spent on each project works out to about half of what you expected.”

I find weeks where I can concentrate unfettered, either at home or at work are the most satisfying and the most productive.

Interesting book, Code Reading: The Open Source Perspective
by Diomidis Spinellis . Chapter Two is available online. It seems to have useful detail and examples. I may have to buy this.