Why this is mistaken
Interval width describes a stated sampling procedure. A large biased sample can produce a narrow interval around the wrong target. Report frame, cutoff, measurement, and processing controls separately from sampling precision.
Where to watch
When this mistake may appear
- The sample is large or observed spread is small.
- The interval appears decision-ready.
Check your work
Your work may contain this mistake if:
- Calls a narrow interval accurate without source controls.
- Assumes margin of error includes undercoverage or miscoding.