---
license: cc0-1.0
language: [en]
pretty_name: "LCSHBench v1.0"
task_categories: [text-classification, text-retrieval]
tags: [library-science, subject-indexing, LCSH, cataloging, multilingual]
configs:
  - config_name: dev
    data_files: dev/dev.jsonl
  - config_name: dev_2k
    data_files: dev_2k/dev_2k.jsonl
  - config_name: test
    data_files: test/test.jsonl
  - config_name: consensus_matched
    data_files: consensus_matched/consensus_matched.parquet
  - config_name: vocab
    data_files: vocab/vocab.jsonl
---

# LCSHBench v1.0

A multilingual, **consensus-grounded** benchmark for Library of Congress Subject
Heading (LCSH) assignment. Ground truth is the agreement of independent research
libraries (Columbia, Harvard, Princeton) cataloging the same work.

## Configs
| config | rows | description |
|---|---|---|
| `dev` | 18,993 | development split (full per-catalog + merged + unanimous GT) |
| `dev_2k` | 2,002 | language-balanced 2K evaluation subset |
| `test` | 3,353 | held-out test inputs; answers in `gt_test.hashed.json` (SHA-256) |
| `consensus_matched` | 1,286,609 | every work cataloged by >=2 libraries: per-library headings (hashed IDs) — the provenance/concordance population |
| `vocab` | 515,281 | LCSH+LCGFT retrieval vocabulary |

## Inter-cataloger concordance (why consensus)
Over 465,187 works cataloged by all three libraries: **93.3%** share a
concept-level heading, only **0.2%** share none (median concept Jaccard 0.86) —
yet just **39.4%** assign identical exact sets and **35.6%** of assertions are
single-source. Subject *identification* is objective; *expression* is subjective.
Human ceiling (a library vs the consensus of the other two): **86.9%** exact /
**93.0%** concept recall.

## Not included
The fine-tuned embedder and te3 embedding indices are **not** released
(model not published; te3 vectors are derived from a hosted API). Raw MARC is
redistributable from the source libraries; rebuild instructions in the repo.

## License & citation
Data: CC0-1.0 (derived from CC0 bulk MARC). Identifiers are hashed.
Built by the v2.2 extraction pipeline. Citation: TBD.