> For the complete documentation index, see [llms.txt](https://docs.hydrosphere.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hydrosphere.io/release-2.4.2/about/hydrosphere-features/data-drift-report.md).

# Data Drift Report

Drift Report service creates a statistical report based on a comparison of training and production data distributions. It compares these two sets of data by a set of statistical tests and finds deviations.

![](/files/-ML7E_d3-V9xZejWo58D)

Drift report uses multiple different tests with p=.95 for different features:

**Numerical** features:

* Levene's test with a trimmed mean 
* Welch's t-test
* Mood's test
* Kolmogorov–Smirnov test

**Categorical** features:

* Chi-Square test
* Unseen categories

## Supported Models

Right now Drift Report feature works only for Models with numerical scalar fields.