Orthographic Constraint Satisfaction and Human Difficulty Alignment in Large Language Models
Summary
The paper examines how well large language models follow strict letter-level rules during generation, a setting where fluent-sounding output is not enough. The test material is 58 daily New York Times Spelling Bee puzzles from summer 2025. Given seven letters, a model must list English words of at least four letters that always contain a designated center letter. The authors run 39 zero-shot configurations from Qwen3 (4B–32B, dense and MoE), Claude Haiku 4.5 and GPT-5-mini, varying reasoning mode and token budget. They compare the outputs with per-word success rates from 10,000 human players per puzzle. Model family matters far more than size. The strongest family roughly doubles the weakest one's F1, mainly through better recall, whereas scaling Qwen3 eightfold yields an 83% gain. Extra thinking budget pays off only for high-capacity models. Model and human difficulty correlate only modestly, and models consistently overlook familiar words with unusual spelling. The released dataset and the diagnosis (models prefer plausible-looking strings over constraint-valid ones) are relevant to any controlled-generation work, though only English was studied.
Key points
- Data and scale: 58 NYT Spelling Bee puzzles (June 2–July 29, 2025) with 2,710 target word instances (2,007 unique words). The setup has 39 configurations × 58 puzzles, giving 2,262 runs. Human difficulty is per-word solver success (3–97%), possibly hint-assisted.
- Cross-family vs. scaling: The cross-family gap is 2.0–2.2× (F1 0.761 vs. 0.343), compared with an 83% gain from Qwen3 4B→32B. A partial-correlation analysis excludes tokenizer design as a within-family confound.
- Thinking budgets: Strong models gain +0.102 to +0.136 F1 from more budget. Qwen3-14B gets worse as budget grows, and the MoE 30B-A3B (3B active parameters) needs a large budget to compensate.
- Human alignment and failures: Spearman ρ between model and human difficulty is 0.28–0.42. Words like "data", "loll" and "acai" are solved by 83–91% of humans but missed by models 94–98% of the time. On 7+ letter words, humans reach 69% success while small models fall to 0.3%.
- Resources: Code and outputs are at GitHub
ReDASers/spelling-bee-llm-eval. The dataset is on Hugging Face asredasers/spelling-bee-human-difficulty.
Cite
@inproceedings{tuck2026orthographic,
title = {{Orthographic Constraint Satisfaction and Human Difficulty Alignment in Large Language Models}},
author = {Tuck, Bryan E. and Verma, Rakesh},
booktitle = {Proceedings of the Fifteenth Language Resources and Evaluation Conference},
year = {2026},
doi = {10.63317/3erhoom72odv},
url = {https://doi.org/10.63317/3erhoom72odv}
}References
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- Budget Pangram Recall (%) Non-Dict FPs/puzzle Qwen-4B Qwen-8B Qwen-14B Qwen-30B Qwen-32B 16K 4K 4K 8K 8K 1.7 2.7 10.5 0.0 15.8 Claude-Haiku GPT-5-mini 16K 16K 47.3 77.6 Table 5: Pangram recall and non-dictionary false positives (words absent from any standard dictionary) per puzzle at each model’s F… find
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