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Why a short interruption costs more than it seems, and the few seconds of marking that make the return easy.
Paper packet. Every task here also exists on screen, where it is checked automatically; answers written on paper are not assessed by Nydus. When you are back at a device, enter your answers there.
You will decide what to do in the seconds before switching, write a marker with where you stopped and what is next, and plan for an interruption you know is coming.
A piece on the desk fades once something else takes the space. A result written on paper does not fade. An interruption is exactly the moment those two facts meet: everything on the desk is about to be pushed off, and there are a few seconds to decide what goes on paper first.
| Term | What it means |
|---|---|
| Interruption | Anything that takes you off a task you mean to come back to. |
| Marker | A short note or object that says where you stopped and what comes next. |
| Resumption cost | The time and mistakes it takes to get going again after an interruption. |
| Sequence error | Skipping a step, or doing one twice, because you lost your place. |
| Interruption lag | The few seconds between noticing an interruption and turning to it. |
When the phone rings halfway through a form, the call feels like the interruption. The real cost comes afterward. Whatever you were holding — which line you were on, the number you were about to type — faded during the call. The return starts with a search: where was I?
Searching takes time, and it causes a particular mistake. You skip a step, or do one twice, because the feeling of I think I did that is not a record.
The fix costs a few seconds, and it is spent before switching, in the interruption lag. Ask three questions in order:
On return, read the marker before touching the task. The return then starts with reading, not searching.
Another way: steps
Before switching: danger? go now. Seconds from done? finish. Otherwise: marker, then go. A marker has two parts: Stopped at: and Next:. On return: read the marker, check the step before it, carry on.
Another way: story
Luis is entering receipts into a spreadsheet when his manager calls him over. He types STOPPED row 31, next: gas receipt 3/14 in the cell beside him, and goes. Forty minutes later he reads the cell, checks row 30 is filled, and starts on the gas receipt. No searching, no row entered twice.
Erik Altmann, Gregory Trafton and David Hambrick (2014) gave people a task made of a fixed sequence of steps. Now and then they interrupted them to type two letters. Interruptions averaging 2.8 seconds doubled the rate of sequence errors afterward. Interruptions of about 4.4 seconds tripled it. Other kinds of mistake did not rise, so the interruptions did not make people careless in general. They made people lose their place.
Three seconds is shorter than a glance at a text message. The point is not that interruptions are bad — many are necessary — but that the place is lost almost at once. The marker is worth writing even when the break will be short.
Gloria Mark, Victor González and Justin Harris (2005) shadowed people at work and recorded every switch. 57 percent of their stretches of work were interrupted. Most interrupted work was picked up again the same day, about 77 percent, but on average only after about 25 minutes, with more than two other tasks done in between.
A later experiment by Mark, Daniel Gudith and Ulrich Klocke (2008) found that interrupted people often finished just as fast, by working faster. They paid for it in stress, frustration and a sense of time pressure. So the cost is not always slower work. Sometimes it is harder work.
Gregory Trafton and colleagues (2003) gave some people an 8-second warning before each interruption and others none. Those with the warning used it to prepare, and they got going again more quickly afterward. A written marker is the same preparation, made to last: it does not depend on remembering what you planned.
To check a marker, read it as if you were someone else. Could that person start the next step from it alone? If it only says page 3, the answer is no. It needs the next action too.
Hospitals have studied interruptions closely, because a lost place can be a wrong dose. Johanna Westbrook and colleagues (2010) observed nurses in two Australian hospitals giving medicines. Each interruption during a round was linked with a rise of about 12 percent in procedural failures, such as skipped checks, and in clinical errors.
Many hospitals, including in the US, have since tried a simple change: a vest or sash that says do not interrupt during a medicine round, and a quiet zone around the cart. It does not make the nurse's desk any bigger. It removes interruptions at the moments when losing one's place matters most, and it saves the rest for after.
Filling in a tax return is a long sequence of steps where a skipped line matters. Phones and computers let you pause notifications for a set time. Turning them off for 45 minutes removes the small interruptions before they happen. For the ones that still come — the doorbell, a call from a child's school — write the marker on the form's margin: Stopped: line 8b. Next: interest from the bank statement. The form will be there when you get back, and so will your place.
It was only a second, so I will remember. The 2014 study is the answer: three seconds was enough to double sequence errors. The feeling that you will obviously know where you were is strongest just before you switch, which is exactly when it is least tested.
Start the whole task again to be safe. That throws away finished work and costs more than the marker would have. Worse, on a task like a form it can mean entering something twice.
Finish everything before answering. Some interruptions cannot wait, and a task minutes from done is not seconds from done. The rule asks which it is.
Ask whether it is urgent or unsafe.
Knock at the door: a delivery, not urgent to the second
Danger is the only reason to go without a pause.
Ask whether the step is seconds from done.
Line 12 needs a number from another document: not seconds
Only a step a few seconds from done is worth finishing first.
Write the marker, with both parts.
Stopped: line 11 done. Next: line 12, total from pay stub.
Where you are and the next action.
Answer the door.
Delivery signed for, 3 minutes
The marker holds the place while the desk is busy.
On return, read the marker before touching the form.
Check line 11 is filled; find the pay stub; start line 12
The return starts with reading, not searching.
Ask whether it is urgent or unsafe.
Oven on; nothing on the stove; the call is a friend
The oven is safe for a few minutes; nothing is burning.
Ask whether the step is seconds from done.
Measuring flour: 2 of 3 cups in the bowl
One more cup takes about ten seconds.
Finish the step.
3 of 3 cups in
A step seconds from done is cheaper to finish than to mark.
Leave a marker for the next step.
Sugar bag set in front of the bowl
An object in the way says what comes next.
On return, read the marker first.
Sugar is in front: flour done, sugar next
No wondering whether the third cup went in.
Ask whether it is urgent or unsafe.
A smoke alarm: possibly unsafe
Safety comes before any marker.
Choose the move.
Go now, without writing anything
The email can be rebuilt; a fire cannot wait.
On return, rebuild the place from the page.
You are halfway through entering 40 names into a sign-up sheet when a coworker asks for help. It is not urgent. What do you do?
You are assembling a bookshelf and have just finished step 6 of 11 when a neighbor knocks. The plan is half written. Fill in the later rows.
| Plan | |
|---|---|
| Urgent or unsafe? | no |
| Seconds from done? | no |
| Stopped | |
| Next | |
| First move on return |
Mark the sentence that saved Priya's place.
This task has no paper form; do it on a device.
A small office logs mistakes in 50 uninterrupted forms and 50 forms that were interrupted partway. Uninterrupted: 3 forms with a skipped or repeated step. Interrupted: 9. Write each as a rate per 100 forms, then how many times as many the interrupted rate is.
Uninterrupted: a per 100. Interrupted: b per 100. That is c times as many.
Choose the move for each interruption.
| Situation | Move |
|---|---|
| Sorting a stack of bills when a friend calls | |
| Typing the last digit of a phone number when the doorbell rings | |
| Writing a long email when the pot boils over | |
| Halfway through a work report when a meeting starts |
You are balancing a checkbook against a bank statement, and a phone appointment is booked for 2:00. Plan for the interruption you know is coming.
| When | Do |
|---|---|
| Before starting | |
| At 1:55 | |
| Just before 2:00 |
Lesson test: one question per skill, one attempt each, no hints. Your answers are checked when you submit.
You are on question 9 of a 15-question job application. Question 9 needs a date from an old letter. The phone rings; it is not urgent. Fill in the move, the marker and the first move on return.
| Part | Plan |
|---|---|
| Move | |
| Stopped | |
| Next | |
| Return |
Without looking back: say the three questions for the seconds before switching, the two parts of a marker, and the first thing to do on return. Next: changing a crowded task so it asks for less at a time. A trial in this course is practice. What is kept is what you wrote on this device today; it is not a score, it is not a test of your memory, and it is never compared with anyone. If you notice trouble with memory or thinking that is new or changing, tell your own doctor or clinician; this course is general practice, not an assessment or treatment. Stopping takes nothing more than closing the page: your place is already saved, and the lesson opens where you left it.
13. Your turn: the smoke alarm goes off mid-email, step 3
Read the draft from the top to find the last full sentence
With no marker, the page itself is the best record.