A common fallacy I encounter repeatedly is that people – at any rate, the younger ones – are able to “Multitask”, that is, attend to multiple actions at once. Since the problem of interruptions in the workplace (and beyond) is a major component of Information Overload, this fallacy is supposed to be comforting. Unfortunately, it is a myth (to borrow from the succinct title of Dave Crenshaw’s book, The myth of multitasking).
Discussing the subject with a friend, she made the point that what people are really doing when they “multitask” is spend some minutes doing one thing, then spend some on another, then on a third (and, I can add from data from Prof. Gloria Mark in UC Irvine, they often don’t get back to the first task until the next day). This sounded familiar, and then it hit me: the mode we were talking about is Preemptive Multitasking, a widely used computing paradigm. This allows the computer to serve many software programs “at once” by allocating very short time slices to them in turn, without asking the interrupted program’s permission. And this may seem like multitasking, but actually it is inefficient because the processing unit has an overhead as it takes care of switching between contexts – much as humans take a 20-40% hit in cumulative time to task completion when they “multitask”.
And what we’d really like to see is a completely different paradigm: we’d love to have brains that are capable of true parallel computing, like today’s multi-core microprocessor chips and like the massively parallel supercomputers out there. Unfortunately, although the brain is massively parallel in many senses – it can process visual data in parallel, and it can keep us breathing while we play chess, for instance – it is not parallel where different cognitive tasks are concerned; it can’t play chess and compose a poem at once, It can’t write two documents at once, and it can’t make quality decisions while reacting to endless incoming email messages at the same time – not without that 20-40% switching overhead.
We are stuck with time sharing brains, not multi-core parallel processors… and we just need to accept this and optimize our behavior accordingly!
I can breath a sigh of relief. Maybe I am instinctively doing the right thing.
I allow only so many communication channels to be open to me, thereby limiting disturbances (=preemptive task switches). Only email and phone – no chat; no twitter.
It is important to cover communication of different immediacies – email is of a minutes/hours/days immediacy, and phone is immediate. There is no need for aditional avenues of the same immediacy to be open for disturbing me.
True, Boaz, though there is much to be said in favor of SMS and IM as immediate channels that are less disruptive than a phone call.