# Interruptions and attention

> What a ping, a switch or an unfinished task costs the mind.

- Page: https://tre-up.com/research/topics/interruptions-and-attention
- Topic 02 of 7 in [Research Notes](https://tre-up.com/research) · Last reviewed 2026-10-07

A notification costs attention even when it is ignored, and switching away from unfinished work leaves part of the mind behind. People make up for interruptions by working faster, and pay for it in stress.

The answer the research points to is not total silence, which brings its own anxiety, but fewer, grouped signals and waiting for natural breaks.

## Questions in this topic

- [Do phone notifications hurt focus, even if I don't check them?](https://tre-up.com/research/do-notifications-hurt-focus): Yes. In a 2015 Florida State University experiment, simply receiving a notification hurt performance on an attention-demanding task about as much as calling or texting, even when people never touched the phone. In a field experiment with 221 adults (Kushlev et al., 2016), people reported more inattention in the week their alerts were on. Markdown: https://tre-up.com/research/do-notifications-hurt-focus.md
- [Should I turn off notifications completely, or batch them?](https://tre-up.com/research/should-i-turn-off-or-batch-notifications): The best evidence favours batching. In a randomized field experiment with 237 people (Duke and Georgetown, 2019), getting notifications in three batches a day made people feel more attentive, productive and in control than the usual stream, while getting none brought few of those benefits and more anxiety and fear of missing out. Markdown: https://tre-up.com/research/should-i-turn-off-or-batch-notifications.md
- [Why is it so hard to get back to work after an interruption?](https://tre-up.com/research/why-is-it-hard-to-get-back-to-work-after-an-interruption): Because part of your attention stays with the task you left. Sophie Leroy's 2009 experiments at the University of Minnesota call this attention residue: people who switched before finishing did worse on the next task, and a 2008 study by UC Irvine and Humboldt University researchers found interrupted people sped up to compensate, at the cost of more stress and frustration. Markdown: https://tre-up.com/research/why-is-it-hard-to-get-back-to-work-after-an-interruption.md

## What this topic rests on (12 sources)

- **My Phone and Me: Understanding People's Receptivity to Mobile Notifications**. Mehrotra A, Pejovic V, Vermeulen J, Hendley R, Musolesi M (2016). Proceedings of CHI 2016, 1021–1032. https://doi.org/10.1145/2858036.2858566
  - Institutions: University of Birmingham (United Kingdom); University College London (United Kingdom); University of Ljubljana (Slovenia); University of Calgary (Canada)
  - Design: Field study with phone logging and experience sampling; sample: 20 people, 10,372 real notifications, 474 questionnaires
  - What it found: How quickly people respond to a notification, and how disruptive it feels, depends on what they are doing: the kind of task, how far through it they are, and how complex it is. It also depends on who sent it and how it is presented. Even important or useful notifications were disruptive at the wrong moment, and personality made a large difference.
  - Where the evidence stops: Twenty people, with many notifications each, and correlational data. It measures response and felt disruption, not long-term benefit.
  - Our summary: https://tre-up.com/research/sources/mehrotra-2016-receptivity
- **The attentional cost of receiving a cell phone notification**. Stothart C, Mitchum A, Yehnert C (2015). Journal of Experimental Psychology: Human Perception and Performance 41(4):893–897. https://doi.org/10.1037/xhp0000100
  - Institutions: Florida State University (United States)
  - Design: Lab experiment
  - What it found: Just receiving a notification hurt performance on a task that needed attention, even when people did not touch their phone. The size of the drop was similar to that of actually using a phone for a call or a text. The authors link it to the notification setting off thoughts unrelated to the task.
  - Where the evidence stops: A lab task, measured over minutes. It shows a cost in the moment, not over a working day.
  - Our summary: https://tre-up.com/research/sources/stothart-2015-notification-cost
- **"Silence Your Phones": Smartphone Notifications Increase Inattention and Hyperactivity Symptoms**. Kushlev K, Proulx JDE, Dunn EW (2016). Proceedings of CHI 2016, 1011–1020. https://doi.org/10.1145/2858036.2858359
  - Institutions: University of Virginia (United States); University of British Columbia (Canada)
  - Design: Field experiment, two one-week conditions; sample: 221 adults
  - What it found: For one week people kept alerts on and their phone within reach; for another, alerts off and the phone away. With alerts on, they reported more inattention and hyperactivity, and more inattention went with lower productivity and well-being.
  - Where the evidence stops: Self-reported symptoms in a general population, not a clinical diagnosis. Two weeks per person.
  - Our summary: https://tre-up.com/research/sources/kushlev-2016-silence-your-phones
- **An in-situ study of mobile phone notifications**. Pielot M, Church K, de Oliveira R (2014). Proceedings of MobileHCI 2014. https://doi.org/10.1145/2628363.2628364
  - Institutions: Telefónica Research (Spain)
  - Design: Field study with phone logging and diaries; sample: 15 people, one week
  - What it found: People handled about 63 notifications a day, mostly from messaging and email, and usually looked at them within minutes, whether or not the phone was on silent.
  - Where the evidence stops: Fifteen people in 2014; today's numbers are likely different. Descriptive, not an experiment.
  - Our summary: https://tre-up.com/research/sources/pielot-2014-in-situ-notifications
- **Productive, Anxious, Lonely: 24 Hours Without Push Notifications**. Pielot M, Rello L (2017). Proceedings of MobileHCI 2017. https://doi.org/10.1145/3098279.3098526
  - Institutions: Telefónica Research (Spain)
  - Design: Field experiment: a day without notifications against a normal day; sample: 30 volunteers
  - What it found: With every notification alert switched off for a day, people felt less distracted and more productive. They also felt less able to respond as others expected, which made some anxious, and less connected. About two thirds planned to change how they handle notifications, and two years later about half still did.
  - Where the evidence stops: Thirty volunteers, one day, self-report.
  - Our summary: https://tre-up.com/research/sources/pielot-rello-2017-24-hours
- **Batching smartphone notifications can improve well-being**. Fitz N, Kushlev K, Jagannathan R, Lewis T, Paliwal D, Ariely D (2019). Computers in Human Behavior 101:84–94. https://doi.org/10.1016/j.chb.2019.07.016
  - Institutions: Duke University (United States); Georgetown University (United States)
  - Design: Randomized field experiment; sample: 237 people
  - What it found: People got notifications as usual, in three batches a day, or never. Batching made them feel more attentive, more productive, in a better mood and more in control of their phone. Getting no notifications at all brought few of those benefits and more anxiety and fear of missing out.
  - Where the evidence stops: Self-reported outcomes over a short field period. Tests batching in general, not any particular app.
  - Our summary: https://tre-up.com/research/sources/fitz-2019-batching-notifications
- **Checking email less frequently reduces stress**. Kushlev K, Dunn EW (2015). Computers in Human Behavior 43:220–228. https://doi.org/10.1016/j.chb.2014.11.005
  - Institutions: University of British Columbia (Canada)
  - Design: Within-person field experiment; sample: 124 adults, two weeks
  - What it found: For one week people checked email only three times a day; for the other, as often as they liked. Daily stress was lower in the limited week, and lower stress went with higher well-being.
  - Where the evidence stops: Email only, two weeks, self-reported stress.
  - Our summary: https://tre-up.com/research/sources/kushlev-dunn-2015-email
- **Effects of intelligent notification management on users and their tasks**. Iqbal ST, Bailey BP (2008). Proceedings of CHI 2008. https://doi.org/10.1145/1357054.1357070
  - Institutions: University of Illinois Urbana-Champaign (United States)
  - Design: System with two user studies
  - What it found: A system held notifications until the person reached a natural break in their task. Delivering at breakpoints, instead of immediately, reduced frustration and reaction time. Which kind of breakpoint suited a notification depended on how relevant its content was.
  - Where the evidence stops: Desktop tasks in a study setting. Detecting breakpoints worked, but telling the types apart was hard.
  - Our summary: https://tre-up.com/research/sources/iqbal-bailey-2008-breakpoints
- **The cost of interrupted work: more speed and stress**. Mark G, Gudith D, Klocke U (2008). Proceedings of CHI 2008, 107–110. https://doi.org/10.1145/1357054.1357072
  - Institutions: University of California, Irvine (United States); Humboldt-Universität zu Berlin (Germany)
  - Design: Lab experiment
  - What it found: Interrupted people finished their tasks faster and just as well, but paid for it: more stress, frustration, time pressure and effort. They seem to make up for interruptions by speeding up.
  - Where the evidence stops: A short lab task. It does not measure how long it takes to get back on track, and gives no minutes figure.
  - Our summary: https://tre-up.com/research/sources/mark-2008-cost-of-interrupted-work
- **If Not Now, When? The Effects of Interruption at Different Moments Within Task Execution**. Adamczyk PD, Bailey BP (2004). Proceedings of CHI 2004, 271–278. https://doi.org/10.1145/985692.985727
  - Institutions: University of Illinois Urbana-Champaign (United States)
  - Design: Lab experiment
  - What it found: Interruptions were placed at different points inside a task, chosen from a model of mental workload. Where in the task the interruption landed changed how people felt and how they judged the interrupter.
  - Where the evidence stops: Lab tasks, short sessions.
  - Our summary: https://tre-up.com/research/sources/adamczyk-bailey-2004-if-not-now
- **Why is it so hard to do my work? The challenge of attention residue when switching between work tasks**. Leroy S (2009). Organizational Behavior and Human Decision Processes 109(2):168–181. https://doi.org/10.1016/j.obhdp.2009.04.002
  - Institutions: University of Minnesota (United States)
  - Design: Two lab experiments
  - What it found: After switching away from an unfinished task, part of a person's attention stays with it, and they do worse on the next task. Finishing the first task, under time pressure, left less of this 'attention residue'.
  - Where the evidence stops: Lab experiments with short tasks.
  - Our summary: https://tre-up.com/research/sources/leroy-2009-attention-residue
- **Attention-Sensitive Alerting**. Horvitz E, Jacobs A, Hovel D (1999). Proceedings of UAI 1999, 305–313. https://www.microsoft.com/en-us/research/publication/attention-sensitive-alerting/
  - Institutions: Microsoft Research (United States)
  - Design: Decision-theory model and system
  - What it found: Treats each alert as a trade: the value of telling someone now against the cost of interrupting them, and the cost of waiting. Applied to email, a system estimated how critical each message was and changed how and when it alerted the person.
  - Where the evidence stops: A model and a system from 1999, not an outcome trial.
  - Our summary: https://tre-up.com/research/sources/horvitz-1999-attention-sensitive-alerting

## Other topics

- [Timing and receptivity](https://tre-up.com/research/topics/timing-and-receptivity): When help lands, and when the same help is just noise.
- [Engagement is not benefit](https://tre-up.com/research/topics/engagement-is-not-benefit): Why opening an app more often is not proof that it helps.
- [Autonomy and wording](https://tre-up.com/research/topics/autonomy-and-wording): Why people push back on advice, and the words that make it easier to hear.
- [Trust and uncertainty](https://tre-up.com/research/topics/trust-and-uncertainty): How people come to rely on automated advice, and how a system should admit what it doesn't know.
- [Learning a person](https://tre-up.com/research/topics/learning-a-person): How a system can help someone it barely knows yet, and why fresh answers beat old patterns.
- [Privacy and deletion](https://tre-up.com/research/topics/privacy-and-deletion): What deleting your data really means, from the law to the backup tape.

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