Multi-agent debate for essay scoring

Advocate, Skeptic and Judge agents score essays without task-specific training.

Automated essay scoring usually depends on supervised models trained for one prompt and one rubric, and a single LLM asked to grade an essay tends to drift toward the middle of the scale and gives little explanation for its score. This line of work, which I lead as first author in the Digital Learning Lab at UC Irvine, asks whether structured interaction between several LLM agents can produce trait-level scores that are both more reliable and easier to inspect.

MADEST (2025) compared three multi-agent designs for trait-level essay scoring: a supervisor that delegates sub-traits to rater agents, rater–reviewer collaboration, and debate between an Advocate (strengths), a Skeptic (weaknesses) and a Judge, with first-token log-probabilities used as a confidence signal when the Judge weighs the two sides (Keramati & Warschauer, 2025). In that evaluation the debate design outperformed the other two, and its agreement with human raters was on a par with the agreement between the two human raters. I presented the comparison as a contributed talk in the NeurIPS 2025 Education Program (Keramati & Warschauer, 2025).

MADRAG (NLP4DH 2026, co-located with ACL) adds retrieval-augmented grounding: before deciding, the Judge compares the essay with retrieved, rubric-aligned scored exemplars (Keramati et al., 2026). On ASAP essay sets 7 and 8, MADRAG substantially outperforms prompt-based LLM baselines and approaches supervised systems without any fine-tuning. Ablations show that retrieval drives the calibration gains, while debate mainly improves higher-level traits such as Ideas and Organization. A qualitative error analysis in the paper catalogues the remaining failure modes, for example a Judge captured by one debater’s framing, which motivated the confidence-diagnostics work described in the next project.

The debate approach also informs the Multi-Agent Review feature of PapyrusAI, the lab’s AI writing coach, and the scorer’s evaluation is preregistered on the Open Science Framework (osf.io/7qpwg). MADRAG was designed and evaluated with Shiyuan Zhou, Sharad Mehrotra and Mark Warschauer.

The MADRAG pipeline: a supervisor assigns rubric traits to debating teams; for each trait an Advocate and a Skeptic argue, and a Judge grounded in retrieved scored essays issues the score (figure from the NLP4DH 2026 paper).

Links: MADRAG paper (arXiv) · ACL Anthology · MADEST poster (Zenodo, CC BY 4.0) · NeurIPS 2025 talk recording

References

2026

  1. MADRAG: Multi-Agent Debate with Retrieval-Augmented Generation for Training-Free Analytic Essay Scoring
    Ali Keramati, Shiyuan Zhou, Sharad Mehrotra, and Mark Warschauer
    In Proceedings of the 6th International Conference on Natural Language Processing for the Digital Humanities, Jul 2026

2025

  1. Poster
    keramati2025madest.png
    MADEST: Multi-Agent Debate Essay Scoring Triangulation
    Ali Keramati and Mark Warschauer
    Sep 2025
    First-year Ph.D. poster
  2. Application of Multi-Agent Systems for Essay Scoring
    Ali Keramati and Mark Warschauer
    In NeurIPS 2025 Education Program (Education Track), San Diego, Dec 2025
    Contributed talk