(Sometimes) Context Switches are Cheap
It is said often in the realm of productivity that context switching is a very expensive operation. Your mind takes time to acclimate to the new task, and thus you waste precious time if you constantly have to switch tasks (either because of an actual change in what you’re working on or because somebody interrupted you). Some believe the cost in context switching can be up to several hours. If you think about how many times while working you’ve replied to a text message, answered the phone or even just stopped briefly to change the song you’re listening to, this amounts to a enormous amount of wasted time.
But that only holds true if you’re really losing all that time every time you get interrupted. While there are definitely cases where a large chunk of uninterrupted work is the optimal choice, there are some situations where a context switch is the optimal scheduling decision. One particular class of work that this applies to are problems requiring a nontrivial amount of insight.
This kind of situation is present in all kinds of professions. Whether you’re stuck in knowing how to progress in proving a mathematical theorem, in engineering software, or writing a book, sometimes putting more conscious effort in doesn’t take you very far. That’s why taking a break, whether it be taking a walk or working on something else might actually be beneficial. This is the kind of multitasking you’re brain was built to do. You have the ability to work on multiple things as long as they’re engaging different parts of your brain.
So are context switches an expensive task you should try to avoid? As with everything, the answer is sometimes.