overthelex/crossjur-citation-coupling
Cross-Jurisdictional Legal Citation Coupling — Ukrainian data & tools Reproducibility artifacts for the paper "Bibliographic Coupling as a Cross-Jurisdictional Evaluation Framework for Legal Case Retrieval: Civil-Law and Common-Law Citation Graphs Compared." The paper compares a civil-law citation graph (Ukrainian, from the EDRSR state court-decision registry) with a common-law one (Canadian, from the COLIEE 2026 Task 1 corpus) under a single coupling / co-citation / temporal… See the full description on the dataset page: https://huggingface.co/datasets/overthelex/crossjur-citation-coupling.
Cross-Jurisdictional Legal Citation Coupling — Ukrainian data & tools
Reproducibility artifacts for the paper "Bibliographic Coupling as a Cross-Jurisdictional Evaluation Framework for Legal Case Retrieval: Civil-Law and Common-Law Citation Graphs Compared."
The paper compares a civil-law citation graph (Ukrainian, from the EDRSR state court-decision registry) with a common-law one (Canadian, from the COLIEE 2026 Task 1 corpus) under a single coupling / co-citation / temporal methodology. This repository holds the tools and the Ukrainian-side derived data so the Ukrainian results can be reproduced and the numbers cited in the paper can be traced to their source.
The Canadian (COLIEE Task 1) texts are not redistributed here — they are governed by the COLIEE data memorandum. The same tools reproduce the Canadian figures from the COLIEE corpus once its licence terms are met.
Update, 25 July 2026
Two changes, both prompted by a re-check of the coupling metrics after the ICTIR '26 framework paper appeared (doi:10.1145/3805713.3820412).
Correction. Earlier versions of the paper stated that Cite(d) was available over the whole Ukrainian pool while the COLIEE side had it only for the labelled query cases, and that the Canadian figures were therefore the only lower bound. That is true of the extraction but not of the outcome: of the 2,217 pool documents with a non-empty citation list, 2,000 are the query cases, and only 3 of the 3,650 pure distractors carry one. Both coupling layers rest on query-case citations, so both sets of figures are lower bounds. Section 3.4, the RQ3 discussion and the Limitations are corrected accordingly. The paper also now reports a corpus property it had omitted: Ukrainian queries carry a mean of 1.31 gold cases (84.5% have exactly one) against 4.12 for the Canadian queries.
New tools.
Outputs are in data/bc_diagnostics_{ua,ca}.json and data/rg_{ua,ca}.json.
Contents
tools/
Standard-library / sentence-transformers Python (and R for figures); no third-party services beyond a PostgreSQL source and, for retrieval, a GPU.
data/ (Ukrainian, derived from EDRSR)
Reproduce the Ukrainian retrieval result
python tools/retrieval_experiment.py \
--zip data/ua_case_retrieval.zip \
--years-json data/ua_years.json \
--models e5 bge-m3 --max-chars 4000 --num-gpus 1 \
--out ua_retrieval_results.jsonHeadline: exponential recency weighting degrades case retrieval in both Ukraine (−37% to −41% at λ=0.2) and Canada (−64% to −67%), while it improves Ukrainian statute retrieval — so the effect tracks the target type (superseded statute vs. cumulative precedent), not the legal tradition. Coupling density, by contrast, is tradition-dependent (Ukrainian decisions couple ~18× more densely than Canadian cases).
Source & ethics
Ukrainian data derives from the public EDRSR (Єдиний державний реєстр судових рішень). Decision texts are truncated and included only as a research benchmark. See also overthelex/ukrainian-court-decisions and overthelex/ua-court-citation-graph.
Citation
Bibliographic Coupling as a Cross-Jurisdictional Evaluation Framework for Legal Case Retrieval. Working draft, 2026 -- UAlberta / COLIEE collaboration; authorship to be finalized.
