IQR and MAD Outlier Review

How to use IQR and MAD Outlier Review

Linear-interpolated quartiles give IQR fences. Modified z uses0.6744897501960817 times centered deviation divided by median absolute deviation. All centering occurs in shifted coordinates to retain small spread at large offsets.

1. Enter numeric observations, iqr multiplier, absolute modified-z threshold.
2. Choose the stated convention and check the units and supported model.
3. Calculate, inspect the result, then copy or download it.

Good to know

• 1–1000observations, positive thresholds. Flags are review prompts, not proof of error. Zero MAD withholds modified-z flags/scores; no data is removed.
• Runs locally. Text/JSON fields are capped at30,000 characters; stricter page-specific and numeric-string limits also apply. Numeric inputs are bounded to magnitude1e15 and nonzero magnitude at least1e-100 unless an exact-string mode states otherwise. Approximate summaries use12 significant digits; CSV numeric cells retain the complete stored value and potentially formula-like string cells gain a protective apostrophe; unsupported, non-finite or detected underflow states return an error.