Heuristic
Flatten nested interruptions when you can
Every extra suspended goal makes the return path harder to see.
When it fits
- You are already handling one interruption and a second request arrives before the first interruption or original task has been closed.
When to avoid it
- The strongest direct evidence here is a small specialized laboratory study. Some environments require nested response; the goal is visibility and control, not a ban.
Why it matters
Avoid creating an interruption stack when the second interruption can wait. Finish, defer or explicitly park the current interrupting task before opening another. A small laboratory study with ICU nurses found that nested interruptions lengthened and degraded resumption compared with serial interruptions. Treat the result as a risk signal: when goals start nesting, make the stack visible and reduce it deliberately.
An example
If you paused an analysis to answer a support issue and another chat arrives, queue the chat unless it actually outranks the support issue instead of creating a third active context.
Check your result
At any point you can name the active task and the suspended stack, and noncritical work is not recursively interrupting other interruptions.
Keep this limit in mind
- The strongest direct evidence here is a small specialized laboratory study. Some environments require nested response; the goal is visibility and control, not a ban.
Connected ideas
Useful withTreat a rule switch as a setup cost
Evidence and sources
In a laboratory study with 30 ICU nurses, nested interruptions produced longer resumption lag and less accurate resumption than serial or baseline interruption conditions.
The sample and task were specialized; nested interruption should be treated as a risk factor rather than a universally quantified cost.
Effects of Nested Interruptions on Task Resumption: A Laboratory Study With Intensive Care Nurses · Abstract