Most crowded days do not collapse because of one dramatic distraction. They wear down through dozens of small switches: a message preview, a quick glance at the inbox, a colleague's "got a minute?". This page is about noticing those switches and changing the ones that are genuinely within your reach.
What the research can and cannot tell us
Gloria Mark, an informatics professor at the University of California, Irvine, has spent around two decades tracking how people move between screens at work. In her 2023 book Attention Span, she reports that the average time spent on one screen before switching has fallen to about 47 seconds in her recent studies. That figure describes the people she observed, mostly knowledge workers, rather than a law of human nature. Still, it matches what many of us feel by mid-afternoon.
An earlier study by Mark, Daniela Gudith and Ulrich Klocke, "The Cost of Interrupted Work" (2008), found something counter-intuitive. People who were interrupted often finished tasks just as quickly, but reported more stress, frustration and time pressure. The cost showed up less in output than in how the work felt.
The organisational researcher Sophie Leroy named a related idea in 2009: attention residue. When we leave one task unfinished to start another, part of our thinking stays behind. Her experiments suggested that performance on the next task suffered, particularly when the first was left incomplete under time pressure.
The aim is not a perfectly quiet day. It is one fewer avoidable switch.
Two kinds of interruption
It helps to separate interruptions that arrive from outside — meetings, calls, notifications, other people — from those we start ourselves, such as opening a news tab when a paragraph gets difficult. Mark's work found self-interruptions to be common, which is quietly encouraging: these are the ones we can experiment with most directly.
Cal Newport's Deep Work (2016) makes a strong case for long, protected blocks of concentration. The idea is useful, but many roles — caregiving, customer support, management — cannot run on four-hour blocks. A realistic goal is often a single 45-minute stretch that is slightly better protected than yesterday's.
Experiments to try this week
- Keep an interruption tally for two days. On a slip of paper, mark each switch with E (external) or S (self-started). Do not try to change anything yet. You are building a baseline.
- Batch one channel. Pick the noisiest source on your tally — often email or team chat — and check it at set times, perhaps once an hour. Let colleagues know if expectations need adjusting.
- Leave a parking note. Before switching away from unfinished work, write one sentence describing the next step. E.J. Masicampo and Roy Baumeister (2011) found that making a specific plan for an unfinished goal reduced intrusive thoughts about it, a possible antidote to attention residue.
- Put the phone in another room for one session. A 2017 study by Adrian Ward and colleagues suggested that a phone's mere presence may drain cognitive capacity. Later replications have been mixed, so treat this as worth testing rather than settled.
A quick comparison
| Interruption | Typical example | What to try | Limit of the evidence |
|---|---|---|---|
| Notification | Chat badge, email preview | Turn off previews; batch checks | Effects vary by role and workload |
| Self-started switch | Opening a tab mid-task | Parking note; phone out of reach | Most studies are short and lab-based |
| Colleague request | "Got a minute?" | Agreed, visible focus hours | Depends heavily on team culture |
| Meeting fragments | 30-minute gaps between calls | Cluster meetings on fewer days | Not always under your control |
How to read your results
After a week, look at your tally again. Did the count fall? More importantly, did even one session feel calmer? Small changes are easy to dismiss, but they are also easy to sustain. If an experiment made no difference, drop it without guilt; that is useful information too.
What this evidence cannot establish is a universal ideal amount of focus time, or that any one technique will suit your brain, your job and your circumstances. Conditions such as ADHD, anxiety or burnout change the picture considerably, and a clinician is a better guide there than a productivity article.
Sources mentioned
- Mark, G. (2023). Attention Span. Hanover Square Press.
- Mark, G., Gudith, D. & Klocke, U. (2008). The cost of interrupted work. CHI Proceedings.
- Leroy, S. (2009). Why is it so hard to do my work? Organizational Behavior and Human Decision Processes.
- Masicampo, E.J. & Baumeister, R.F. (2011). Consider it done! Journal of Personality and Social Psychology.
- Ward, A.F. et al. (2017). Brain drain. Journal of the Association for Consumer Research.
- Newport, C. (2016). Deep Work. Grand Central.