GRIM & GRIMMER Test
Checks a reported mean (and optionally SD) against the sample size: the mean of N integer scores can only land on multiples of 1/N, so many published means are simply impossible. The GRIM test (Brown & Heathers 2016) caught dozens of papers this way; GRIMMER (Anaya 2016) extends the idea to standard deviations. Paste numbers straight from any paper.
Read the full guide to this tool
Results
Notes
- The mean of N integers must be a multiple of 1/N. After rounding to d decimals, a reported mean is only consistent if some integer total lands within half a rounding step.
- GRIM has power when N × items is small — below roughly 100 for two-decimal means. With larger samples every value passes and the test is silent, not affirmative.
- An inconsistent value is not proof of fraud: check first for dropped participants, non-integer scales, weighting, or transcription typos.
Explore the idea
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