Math-Specialized or General-Purpose? A Comparison of MathBERT and DeBERTa-v3-large for Automated Scoring of Mathematics-Explanation Items

Gregory M. Jacobs, Ahmed H. Bediwy, Martha Bellows


Abstract
Automated scoring of math-explanation items should handle responses that mix natural language with symbolic reasoning. The 2023 NAEP Automated Scoring Challenge showed that fine-tuning pre-trained encoders can reach human-like agreement, but its winning system. used a large, general-purpose encoder, while smaller math-specific pre-trained encoders remain a plausible and more efficient alternative. We fine-tune MathBERT (110M parameters) and DeBERTa-v3-large (183M parameters) as single-output regression scorers on 31 math-explanation items from one statewide summative assessment administration, benchmarking every model against human–human reliability and summarizing deployability with a three-tier acceptance criteria. On the 18 items fine-tuned under both encoders with identical datasets, the resulting performance between the two was practically indistinguishable: mean best QWK was 0.931 for MathBERT and 0.933 for DeBERTa-v3-large—a difference of only 0.002—and the models traded top performance at similar rates. Given similar performance, we tested a two-stage approach that used the larger general-purpose encoder only when the smaller math-focused encoder failed acceptance criteria. Extending MathBERT to all 31 items, it reached a mean QWK of 0.926 against a human–human benchmark of QWK = 0.940 and met operational acceptance criteria on 81% of items. Escalating the six items where a fine-tuned MathBERT model failed acceptance to a fine-tuned DeBERTa-v3-large model recovered four of the six, yielding acceptable automated-scoring models for 29 of 31 items. Because the smaller, math-pre-trained encoder matches the larger one at roughly 40% fewer parameters, we recommend fine-tuning a MathBERT encoder as the default and escalating to the larger, general purpose encoder like DeBERTa- v3-large only when a MathBERT model fails when deploying automated scoring models operationally at scale for math-explanation items.
Anthology ID:
2026.aimecon-wip.25
Volume:
Proceedings of the Artificial Intelligence in Measurement and Education Conference (AIME-Con): Works in Progress
Month:
October
Year:
2026
Address:
Wyndham Grand Pittsburgh Downtown, Pittsburgh, Pennsylvania, United States
Editors:
Joshua Wilson, Christopher Ormerod, Magdalen Beiting-Parrish
Venue:
AIME-Con
SIG:
Publisher:
National Council on Measurement in Education (NCME)
Note:
Pages:
193–199
Language:
URL:
https://aclanthology.org/2026.aimecon-wip.25/
DOI:
Bibkey:
Cite (ACL):
Gregory M. Jacobs, Ahmed H. Bediwy, and Martha Bellows. 2026. Math-Specialized or General-Purpose? A Comparison of MathBERT and DeBERTa-v3-large for Automated Scoring of Mathematics-Explanation Items. In Proceedings of the Artificial Intelligence in Measurement and Education Conference (AIME-Con): Works in Progress, pages 193–199, Wyndham Grand Pittsburgh Downtown, Pittsburgh, Pennsylvania, United States. National Council on Measurement in Education (NCME).
Cite (Informal):
Math-Specialized or General-Purpose? A Comparison of MathBERT and DeBERTa-v3-large for Automated Scoring of Mathematics-Explanation Items (Jacobs et al., AIME-Con 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.aimecon-wip.25.pdf