The Cost of Context Switching

During a recent workshop with the awesome Rich Mironov (author of The Art of Product Management), Rich had everyone at the workshop do a simple and quick exercise that clearly shows the cost of context switching.

It is amazing, but there are still people who believe they can do it all by multitasking, even though multiple studies show this is not the case. Humans simply do not multitask well.

I knew a designer that complained about a developer who focused on tasks in a linear order. The designer wanted the developer to multitask. The problem is that constantly context switching as the designer wanted would have slowed the developer down, but seeing smaller bits of progress across a portfolio of tasks gave the designer a sense that more work was being accomplished.

Unfortunately, the designer had it wrong. Psychiatrist Edward M. Hallowell even goes so far as to describe multitasking as a “mythical activity in which people believe they can perform two or more tasks simultaneously as effectively as one.” Worse, our work days are now a constant stream of interruption, and it takes the brain about 10 to 15 minutes to recover from interruptions. That is a lot of lost productivity. This one reason why some believe open floor plans are detrimental to productivity.

Don’t believe it? Think you can truly multitask? Take the challenge and find out.

The Test

If you think you are an effective multitasker or want to understand the cost of context switching, try this:

  1. Take a blank piece of paper, draw three columns (top to bottom), label them 1 to 10, A to J, and I to X (Roman numerals).
  2. Time yourself filling out each column going from left to right. So the first row is 1, A, I, then do the next until you reach X.
  3. Note your time.
  4. Turn over the paper draw three columns (top to bottom), label them 1 to 10, A to J, and I to X—just like before.
  5. Time yourself filling in the columns, from top down starting with 1 to 10, then A to J, then I to X,
  6. Got your time?


If your time was equal for both, you are the rare human who can actually multitask—but your time is not the same is it? You did the second version much faster. In fact, if you do this with a group of people, you should see the second run-through taking around half the time. Why? The first time through, you were context switching from column to column, but the second time, there was very little context switching.

Headphone Rule

So before you interrupt a coworker, tapping on the shoulder of that person with the headphones on, remember that tap is going to cost productivity. At one company, we had a headphone rule. If someone was wearing headphones you could not bother them, no headphones and you could ask if they had a moment.

Small Spaces

One way to make open floor plans work is to provide a variety of spaces: open, small cubbies, and small group spaces. This will help people find the space they need to collaborate or be productive on their own. Vitra’s Highback Alcove sofa by designers Ronan and Erwan Bouroullec is one example of how to create a private space within an open space.

The Power of Focus

Since multitasking can cost you 15 IQ points, and as we saw in the experiment above, you can work up to twice as fast when you are in the flow with less context switching, it should be clear—it’s focus for the win.