Reliable machine learning / Research software

Oliver Hennhöfer

Research staff at Hochschule Karlsruhe working on reliable machine learning systems.

I work on statistical methods and software for machine learning systems that need to stay reliable under uncertainty. My current focus is conformal inference for anomaly detection, uncertainty quantification, and online false discovery rate control.

I am especially interested in settings where data are scarce, noisy, non-stationary, or arrive sequentially. Recent work studies low-data conformal anomaly detection, shift-aware weighted procedures, and practical Python interfaces that turn anomaly scores into calibrated p-values and FDR-controlled decisions.

In parallel to the theory, I build research software for reproducible experiments and applied workflows. The current toolchain includes nonconform for conformal anomaly detection and online-fdr for sequential multiple testing when hypotheses arrive over time.

  • Anomaly Detection
  • Conformal Inference
  • Uncertainty Quantification
  • False Discovery Rate Control
  • Sequential Testing
  • Research Software
Project 01

nonconform

Conformal anomaly detection and change-point detection for turning anomaly scores into calibrated p-values, with split, cross, and weighted conformal workflows plus FDR-controlled decisions.

Python, conformal inference, anomaly detection, FDR control

Project 02

online-fdr

Sequential multiple-testing procedures for online FDR and FWER control, including one-by-one APIs for LORD, SAFFRON, ADDIS, alpha-spending, and batch baselines.

Python, online FDR, FWER, sequential testing

Project 03

oddball

A lightweight collection of anomaly detection datasets for reproducible experiments.

Python, datasets, benchmarks

Project 04

aberrant

Online anomaly detection algorithms for streaming settings.

Python, streaming, anomaly detection

Publication 2026

Conformal Anomaly Detection in Python: Moving Beyond Heuristic Thresholds with 'nonconform'

Oliver Hennhöfer, Maximilian Kirsch, Christine Preisach

Preprint, arXiv:2605.13642

Publication 2026

Between Resolution Collapse and Variance Inflation: Weighted Conformal Anomaly Detection in Low-Data Regimes

Oliver Hennhöfer, Christine Preisach

Preprint, arXiv:2603.23205

Publication 2024

Leave-One-Out-, Bootstrap- and Cross-Conformal Anomaly Detectors

Oliver Hennhöfer, Christine Preisach

IEEE ICKG 2024, pp. 110-119