UniTor at Cruciverb-IT: Retrieval-Augmented Two-Step Reasoning for Italian Crossword Clue Answering
Paper · 2026 · Andriy Shcherbakov, Danilo Croce and Roberto Basili
Summary
The paper addresses Italian crossword clue answering in Cruciverb-IT Task 1 at EVALITA 2026. Given a clue and the exact length of the answer, a system must return candidate solutions ranked by confidence. The authors present UniTor, an LLM-based solver that treats the task as constrained ranking and uses no task-specific fine-tuning.
UniTor first retrieves length-compatible examples from a large repository of clue–solution pairs. The authors compared lexical, neural and hybrid retrieval and chose neural retrieval for the final system. The retrieved examples serve as few-shot evidence in a prompt that runs in one model call and has two stages. The model first brainstorms a varied set of candidates. It then removes candidates of the wrong length, after normalizing them to uppercase A–Z, and re-ranks the rest with explicit confidence scores.
Ablations show that retrieval and two-step reasoning help in complementary ways, and that retrieval lets smaller models narrow the gap with larger ones. UniTor ranked first in the official evaluation. The results suggest that careful prompting and retrieval can compete with training-heavy approaches on knowledge-intensive tasks with loosely specified inputs.
Key points
- Official results: UniTor scored Accuracy@1 0.69, Accuracy@10 0.83 and MRR 0.72. The second-best system scored 0.58 / 0.75 / 0.63, and the BM25 baseline scored 0.40 / 0.62 / 0.46.
- Margins: UniTor beat the second-best system by +0.11 in Accuracy@1 and +0.09 in MRR. It beat the average of all submitted runs by +0.17 in Accuracy@1 and +0.15 in MRR.
- Final configuration: the system uses k = 10 retrieved suggestions, two-step prompting and probabilistic output with the GLM model. Configurations based on GPT-OSS also beat the baseline and most competing systems.
- Research questions: the study tests whether asking for probability scores beats plain list generation and whether two-step prompting beats single-pass inference. It also examines the effect of model scale and how retrieval interacts with scale and prompting.
- Limitations and future work: the system answers isolated clues without grid or crossing-letter information. The authors propose integrating it into a full grid solver where UniTor's scores would act as soft constraints.
Fields, topics and concepts
📚 Shelves 2The field of science this work belongs to (OpenAlex fields).Computer Science · 16,667 worksArtificial Intelligence · 16,194 works
🧭 Topics 2Research subjects and languages the work is about.Reasoning · 1,426 worksInformation retrieval & search · 473 works
Cite
Cite as Andriy Shcherbakov, Danilo Croce and Roberto Basili. 2026. UniTor at Cruciverb-IT: Retrieval-Augmented Two-Step Reasoning for Italian Crossword Clue Answering. Proceedings of the Ninth Evaluation Campaign of Natural Language Processing and Speech Tools for Italian. Final Workshop (EVALITA 2026).
@inproceedings{shcherbakov2026unitor,
title = {{UniTor at Cruciverb-IT: Retrieval-Augmented Two-Step Reasoning for Italian Crossword Clue Answering}},
author = {Andriy Shcherbakov, Danilo Croce and Roberto Basili},
booktitle = {Proceedings of the Ninth Evaluation Campaign of Natural Language Processing and Speech Tools for Italian. Final Workshop (EVALITA 2026)},
year = {2026},
url = {https://aclanthology.org/2026.evalita-1.41/}
}References
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