# IQR, Tukey's Fences and Adjusted Boxplot: Outlier Detection in Skewed Data

> Source: https://sukruyusufkaya.com/en/learn/anomali-tespiti/iqr-tukey-adjusted-boxplot
> Updated: 2026-05-13T13:04:48.656Z
> Category: Anomali Tespiti
> Module: Module 2: Statistical Foundations
**TLDR:** Interquartile Range (IQR), Tukey's fences (k=1.5 / k=3), boxplot anatomy, and adjusted boxplot with medcouple for skewed data — robust alternatives where z-score fails.