The sniper fallacy adjusts the data to make it appear to confirm a conclusion. Hits are selected and misses are ignored, creating false patterns.
Example
“I dreamed of 7. The number 362 appeared, and 3+6-2 is 7. Therefore it was a premonition.”
(The fit is forced after the fact.)
Applied example (political)
“Only the districts where the poll was right are shown, and success is declared.” (Failures are ignored.)
Applied example (mystical)
“Only healings are counted and non-improvements are omitted.” (Favorable evidence is selected.)
Why it is fallacious
- Evidence is chosen after knowing the result.
- Contradictory data are ignored.
- Coincidences are mistaken for real patterns.
How to spot it
- Results are “fitted” with ad hoc rules.
- Only favorable cases are shown.
- No pre-defined evaluation criteria.
How to respond
- Ask for criteria defined before analyzing data.
- Require the full sample, including misses.
- Compare against base rates and controls.