Why this is mistaken
A fence flags an observation for investigation. Verify the source and population rule, then document correction, retention, separate modeling, or justified exclusion. Do not let the preferred result choose the treatment.
Where to watch
When this mistake may appear
- A value lies beyond a quartile fence.
- Removing one observation makes a result cleaner or more favorable.
Check your work
Your work may contain this mistake if:
- Deletes 78 days without source evidence.
- Keeps a verified duplicate merely because all data should remain.