Connor Jason
2026
NEAT-IR: Neural Explainable Analysis Tool for Information Retrieval
Lev Sukherman | Artem Frenk | Nina Klimenkova | Connor Jason
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Lev Sukherman | Artem Frenk | Nina Klimenkova | Connor Jason
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026)
Neural IR models achieve strong performance but remain difficult to interpret. We present NEAT-IR, a black-box analysis framework that explains ColBERT’s ranking behavior using 26 classical IR features (BM25, TF-IDF, IDF measures, positional signals). We analyze ColBERT through two complementary lenses: regression (predicting exact scores) and learning-to-rank (predicting relative order), evaluated on MS MARCO (48,250 query-passage pairs). Our key finding is a score-rank gap: classical features preserve ColBERT’s rankings nearly perfectly (NDCG@5 ≈ 0.99) yet explain only R2 ≈ 0.28 of score variance. Feature attribution reveals that regression and ranking models rely on distinct feature subsets: query-level IDF signals dominate score prediction, while document-matching features (BM25, cosine TF-IDF) drive ranking preservation. These findings suggest that ColBERT’s ordinal behavior on MS MARCO is largely recoverable from classical signals, while neural contributions primarily affect score magnitude. NEAT-IR enables practitioners to diagnose when neural rankers deviate from classical patterns, supporting interpretable model auditing and informed hybrid pipeline design.