IQR
Units & Measurements abbreviation · Statistics
| Stands for | Interquartile range |
|---|---|
| Categories | Units & Measurements |
IQR stands for Interquartile range, a statistics abbreviation also used in medicine.
The spread of the middle half of a data set: the third quartile minus the first quartile (Q3 − Q1). It resists outliers, which makes it a better measure of spread than the SD for skewed data such as incomes or hospital stays.
Example: Median wait time was 14 days (IQR 7 to 28).
Usage notes
Box plots draw the IQR as the box, and Tukey's rule flags points more than 1.5 × IQR beyond the quartiles as potential outliers. Medical journals often report a median with its IQR for non-normal data. For a normal distribution the IQR is about 1.35 SD.
Related abbreviations
More statistics abbreviations
- GLM – Generalized linear model
- H0 – Null hypothesis
- H1 – Alternative hypothesis
- HR – Hazard ratio
- ICC – Intraclass correlation coefficient
- iid – Independent and identically distributed
- IV – Instrumental variable
- KDE – Kernel density estimation
- KS – Kolmogorov-Smirnov (test)
- LASSO – Least absolute shrinkage and selection operator
- LDA – Linear discriminant analysis
- LLN – Law of large numbers