The brain swaps rules each time you jump from one job to another. Each swap is small, but experiments find they add up in lost time and extra mistakes.
Pick a kind of switch to see what the research says about it. The bar shows how large the cost of switching tends to be.
Based on the American Psychological Association's summary of task-switching research and UK THINK! road safety guidance. General information only.
TWO NUMBERS WORTH KNOWING
Small breaks, big slips.
One lab finding on interruptions, one road safety figure.
2× errors
Error rate after a 3-second interruption
In a study of 300 people reported by Lab Manager, interruptions of about three seconds, such as typing two letters, doubled the error rate on a step-by-step computer task.
INTERRUPTIONS · MICHIGAN STATE
4× more likely
Crash risk when using a phone
The UK road safety campaign THINK! says you are 4 times more likely to be in a crash if you use your phone while driving.
PHONES AND DRIVING · THINK!
A Stanford study of about 100 students, published in 2009, found that heavy media multitaskers did worse than light multitaskers at ignoring distractions and at switching between tasks.
FOUR HABITS TO TRY
Fewer switches, calmer work.
These follow from the research rather than from any one study. None of them needs an app, only a little planning.
Batch similar jobs
Group emails, calls or forms together so you change the mental rules less often.
Finish the step first
In one study, three-second interruptions doubled slips on a step-by-step task, so reach a natural pause before you look away.
Do the unfamiliar thing alone
Switch costs were larger for new and complex tasks, so give them an unbroken block.
Put the phone out of reach
Face down at work, and out of your hands completely when you drive.
AI-generated image, not a photograph of a real person or place.
PHONES AND DRIVING
The road needs all of you.
AI-generated image, not a photograph of a real person or place.
The APA notes that losing even half a second to task switching can matter for a driver on a phone at 30 mph. In Great Britain it is illegal to use a hand-held phone or similar device for any purpose while driving, even at traffic lights or in a queue.
THINK! says the penalty is 6 points and a £200 fixed penalty, and new drivers who get 6 points in the first 2 years lose their licence. Hands-free use is not a specific offence, but police can still act if it distracts you.
Questions
Questions people ask
Can people really multitask?
The APA describes multitasking as doing tasks at once, switching between them, or doing them in rapid succession. Experiments consistently find people lose time when they switch from one task to another.
How much time does a switch cost?
Each switch can cost just a few tenths of a second. The cost grows with complex or unfamiliar tasks, and frequent switching adds up. One researcher suggested it can cost as much as 40 percent of productive time.
Do short interruptions matter?
In a Michigan State University study of 300 people, interruptions of about three seconds doubled the error rate on a sequence-based task.
Are heavy multitaskers better at switching?
Not in a 2009 Stanford study of about 100 students: heavy media multitaskers did worse than light multitaskers at a task that required switching between letter and number judgements.
Is hands-free phone use legal while driving?
THINK! says hands-free use is not a specific offence like hand-held use, but police can still prosecute if it distracts you and affects your driving.
