Principle
Stop the search when the next evidence is unlikely to change the decision
A search can be methodical without being infinite.
When it fits
- Research continues because another paper can always be found.
When to avoid it
- Do not use a practical stopping rule for tasks that explicitly require exhaustive systematic retrieval.
Why it matters
Use a stopping rule matched to the job. For formal reviews, follow the required completeness-oriented protocol. For bounded decision research, stop when additional searches mostly yield duplicates and the remaining uncertainty is unlikely to change the action, confidence boundary or safety decision. Record what remains unknown.
An example
Stop a tool-buying evidence review once new sources repeat the same compatibility limits and no unresolved issue could change the purchase decision.
Check your result
The stopping decision can be explained by diminishing evidence value rather than fatigue or confirmation of a preferred answer.
Keep this limit in mind
- Do not use a practical stopping rule for tasks that explicitly require exhaustive systematic retrieval.
Evidence and sources
Cochrane explicitly discusses when to stop searching and treats search as an iterative process whose stopping point should be justified.
Stopping rules differ between formal completeness-oriented reviews and practical decision research.
Chapter 4: Searching for and selecting studies · When to stop searching