Eric Modesitt

ML Researcher — AI Safety, LLM Reliability & Interpretability

Berkeley, California

Builder–researcher focused on the reliability, robustness, and safety of large language models. Currently an Anthropic Fellow researching when activation-probe safety monitors fail and how to predict failure before deployment. Background spans statistical guarantees for LLM inference, large-scale data curation, and production ML reliability.

Now

AI Safety Fellow, Anthropic Fellows Program
Aug 2026–present · Berkeley, CA

Safeguards-mentored research project studying when activation-probe safety monitors fail — mapping failure modes of linear probes for policy enforcement and predicting probe performance from the written policy itself.

Research & Publications

ORBIT: Cost-Effective Dataset Curation for Large Language Model Domain Adaptation with an Astronomy Case Study

ACL 2025 Findings · First author

Eric Modesitt, Ke Yang, Spencer Hulsey, Chengxiang Zhai, Volodymyr Kindratenko

Refined the 1.3T-token FineWeb-Edu corpus into a 10B-token astronomy subset; fine-tuning LLaMA-3-8B on the curated data improved MMLU astronomy from 69% to 76%. The method was also validated on law and medicine. Datasets, code, and model are open-sourced.

Sequential Multi-Persona Direct Logit Inference (SMP-DLI)

Working paper · 2025

A sequential LLM inference system that adaptively allocates compute based on confidence: calibrated uncertainty estimates, statistical early stopping, and methods for knowing when models should abstain.

Scalable Oversight Through Human-AI Complementarity for Harm Detection

Paper in preparation · SPAR, Spring 2026

SPAR (Supervised Program for Alignment Research), methods team; project led by Rishub Jain (Google DeepMind)

Methods for increasing human–AI complementarity on harm-identification tasks: a learned (LoRA-based) confidence signal and learned routing for combining human and AI judgments. Designed the team's calibration protocol.

civic-evals — Civic Information Reliability

CORDA Democracy Fellowship · 2026

1st cohort, Project 03; Fellow (one of six); project led by Justin Shenk (BlueDot Impact)

An open evaluation suite, built on inspect-ai, measuring how reliably LLMs answer civic questions — 1,214 graded answers across 8 evals and 9 scorers. Fellows built the persona-drift taxonomy, sycophancy and demographic-bias analyses, and a cross-model bias study on byte-identical candidate profiles differing only in policy direction.

Experience

Education