---
configs:
  - config_name: DDC
    default: true
    data_files:
      - split: train
        path:
          - DDC.jsonl.gz
  - config_name: LCC
    data_files:
      - split: train
        path:
          - LCC.jsonl.gz
  - config_name: UDC
    data_files:
      - split: train
        path:
          - UDC.jsonl.gz
language:
- en
multilinguality:
- monolingual
size_categories:
- 1K<n<10K
task_categories:
- text-classification
task_ids:
- multi-class-classification
pretty_name: Library Classification Systems
tags:
- library-science
- information-organization
- ontology
---

# Library Classification Systems

## Dataset Summary

This dataset contains hierarchical outlines of three major library classification systems: Dewey Decimal Classification (DDC), Library of Congress Classification (LCC), and Universal Decimal Classification (UDC).

The dataset provides the freely-available outlines of DDC, LCC, and UDC classification systems commonly used in libraries. It contains the hierarchical structure and descriptions for each classification, but not the full text which must be purchased separately. The data is formatted as JSONL files with fields for call numbers, descriptions, broader categories, and narrower subcategories.

## Supported Tasks and Leaderboards

This dataset can support tasks related to:

- Hierarchical text classification
- Library science and information organization 
- Ontology and knowledge graph construction

## Languages

The descriptions are in English.

## Data Structure

### Data Instances

Each instance in the dataset represents a library classification entry. The structure is designed to capture the hierarchical nature of the classification scheme.

### Data Fields

- `call_number`: string
  - The alphanumeric call number that uniquely identifies the classification
  - Example: `"AC1-999"`

- `description`: string
  - A textual description of the classification topic or subject area
  - Example: `"Collections. Series. Collected works"`

- `broader`: string or null
  - The call number of the parent/broader classification
  - Null for root-level classifications
  - Example: `null` (for a top-level classification)

- `narrower`: list of strings
  - An array of call numbers representing child/narrower classifications
  - Example: `["AC1-195", "AC200", "AC801-895", "AC901-995", "AC999"]`

### Example Instance

```json
{
  "call_number": "AC1-999",
  "description": "Collections. Series. Collected works",
  "broader": null,
  "narrower": ["AC1-195", "AC200", "AC801-895", "AC901-995", "AC999"]
}
```

This structure allows for efficient navigation and querying of the classification hierarchy, enabling users to traverse from broader to narrower topics and vice versa.

### Data Splits

The full dataset contains:

- 1,110 DDC entries
- 6,517 LCC entries
- 2,431 UDC entries

Total: 10,058 entries

## Dataset Creation

### Curation Rationale

This dataset was curated to provide open access to the hierarchical structure of major library classification systems. It aims to support research, education, and innovation in information organization and retrieval.

### Source Data

The dataset is derived from the publicly available outlines of the Dewey Decimal Classification (DDC), Library of Congress Classification (LCC), and Universal Decimal Classification (UDC). Full classification texts are proprietary and require purchase from the respective organizations.

#### Initial Data Collection and Normalization

Classification outlines were collected on 2024-09-18 from the following authoritative sources:

- Library of Congress Classification (LCC): ["Library of Congress Classification Outline"](https://www.loc.gov/catdir/cpso/lcco/)
- Universal Decimal Classification (UDC): ["Universal Decimal Classification Summary"](https://vocabs.rossio.fcsh.unl.pt/pub/udcS/en/) (ROSSIO Vocabulary Server)
- Dewey Decimal Classification (DDC): ["Dewey Services - Resources"](https://www.oclc.org/en/dewey/resources.html) (OCLC)

Versions used:
- UDC Master Reference File (UDC MRF) 2011
- DDC 23 Summaries

Data processing steps:
1. DDC: The summary PDF was downloaded and manually formatted for consistency.
2. LCC: Microsoft Word files were converted to plain text, with headings and call numbers extracted programmatically.
3. UDC: The `udc-summary.rdf` file was parsed using RDFlib, retaining only English labels.

## Considerations for Using the Data

### Social Impact of Dataset

This dataset expands access to library classification knowledge, potentially:
- Facilitating research in information science and digital humanities
- Supporting the development of improved information retrieval systems
- Enhancing educational resources for library and information science students

### Discussion of Biases

Users should be aware that library classification systems may reflect historical, cultural, and geographical biases in knowledge organization. These biases could manifest as:
- Overrepresentation of Western perspectives
- Outdated terminology or categorizations for certain topics
- Uneven depth of coverage across different subject areas

### Known Limitations

1. Scope: The dataset includes only freely available outlines, not the complete classification texts.
2. Granularity: The level of detail varies between classification systems and within subject areas.
3. Currency: Updates to the original classification systems may not be immediately reflected in this dataset.
4. Structural differences: The UDC system's structure, with its main and auxiliary tables, differs slightly from DDC and LCC, which may affect comparisons.

## Additional Information

### Dataset Curators

Alan Tseng

### Licensing Information

Creative Commons Attribution 4.0 International (CC BY 4.0)