glam/docs/nlp_extractor.md
2025-11-19 23:25:22 +01:00

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# NLP Institution Extractor
## Overview
The `InstitutionExtractor` class provides NLP-based extraction of heritage institution data from unstructured conversation text. It uses pattern matching, keyword detection, and heuristic rules to identify museums, libraries, archives, galleries, and other GLAM institutions.
## Features
- **Institution Name Extraction**: Identifies institution names using capitalization patterns and keyword context
- **Type Classification**: Classifies institutions into 13 types (MUSEUM, LIBRARY, ARCHIVE, GALLERY, etc.)
- **Multilingual Support**: Recognizes institution keywords in English, Dutch, Spanish, Portuguese, French, German, and more
- **Identifier Extraction**: Extracts ISIL codes, Wikidata IDs, VIAF IDs, and KvK numbers
- **Location Extraction**: Identifies cities and countries mentioned in text
- **Confidence Scoring**: Assigns 0.0-1.0 confidence scores based on available evidence
- **Provenance Tracking**: Records extraction method, date, confidence, and source conversation
## Installation
The extractor is part of the `glam_extractor` package and has no external NLP dependencies (uses pure Python pattern matching).
```python
from glam_extractor.extractors.nlp_extractor import InstitutionExtractor
```
## Usage
### Basic Text Extraction
```python
from glam_extractor.extractors.nlp_extractor import InstitutionExtractor
extractor = InstitutionExtractor()
text = "The Rijksmuseum in Amsterdam (ISIL: NL-AsdRM) is a major art museum."
result = extractor.extract_from_text(text)
if result.success:
for institution in result.value:
print(f"{institution.name} - {institution.institution_type}")
print(f"Confidence: {institution.provenance.confidence_score}")
```
### Extracting from Conversation
```python
from glam_extractor.parsers.conversation import ConversationParser
from glam_extractor.extractors.nlp_extractor import InstitutionExtractor
# Parse conversation file
parser = ConversationParser()
conversation = parser.parse_file("path/to/conversation.json")
# Extract institutions
extractor = InstitutionExtractor()
result = extractor.extract_from_conversation(conversation)
if result.success:
print(f"Found {len(result.value)} institutions")
for inst in result.value:
print(f"- {inst.name} ({inst.institution_type})")
```
### With Provenance Tracking
```python
result = extractor.extract_from_text(
text="The Amsterdam Museum has ISIL code NL-AsdAM.",
conversation_id="conv-12345",
conversation_name="Dutch Heritage Institutions"
)
if result.success and result.value:
institution = result.value[0]
# Access provenance metadata
prov = institution.provenance
print(f"Data Source: {prov.data_source}") # CONVERSATION_NLP
print(f"Data Tier: {prov.data_tier}") # TIER_4_INFERRED
print(f"Confidence: {prov.confidence_score}")
print(f"Method: {prov.extraction_method}")
print(f"Conversation: {prov.conversation_id}")
```
## Extracted Data Model
The extractor returns `HeritageCustodian` objects with the following fields populated:
| Field | Description | Example |
|-------|-------------|---------|
| `name` | Institution name | "Rijksmuseum" |
| `institution_type` | Type enum | `InstitutionType.MUSEUM` |
| `organization_status` | Status enum | `OrganizationStatus.UNKNOWN` |
| `locations` | List of Location objects | `[Location(city="Amsterdam", country="NL")]` |
| `identifiers` | List of Identifier objects | `[Identifier(scheme="ISIL", value="NL-AsdRM")]` |
| `provenance` | Provenance metadata | See below |
| `description` | Contextual description | Includes conversation name and text snippet |
### Provenance Fields
Every extracted record includes complete provenance metadata:
```python
provenance = Provenance(
data_source=DataSource.CONVERSATION_NLP,
data_tier=DataTier.TIER_4_INFERRED,
extraction_date=datetime.now(timezone.utc),
extraction_method="Pattern matching + heuristic NER",
confidence_score=0.85,
conversation_id="conversation-uuid",
source_url=None,
verified_date=None,
verified_by=None
)
```
## Pattern Detection
### Identifier Patterns
The extractor recognizes the following identifier patterns:
- **ISIL codes**: `[A-Z]{2}-[A-Za-z0-9]+` (e.g., `NL-AsdRM`, `US-MWA`)
- **Wikidata IDs**: `Q[0-9]+` (e.g., `Q924335`)
- **VIAF IDs**: `viaf.org/viaf/[0-9]+` (e.g., `viaf.org/viaf/123456789`)
- **KvK numbers**: `[0-9]{8}` (Dutch Chamber of Commerce)
### Institution Type Keywords
Multilingual keyword detection for institution types:
```python
InstitutionType.MUSEUM: [
'museum', 'museo', 'museu', 'musée', 'muzeum', 'muzeul',
'kunstmuseum', 'kunsthalle', 'muzej'
]
InstitutionType.LIBRARY: [
'library', 'biblioteca', 'bibliothek', 'bibliotheek',
'bibliothèque', 'biblioteka', 'national library'
]
InstitutionType.ARCHIVE: [
'archive', 'archivo', 'archiv', 'archief', 'archives',
'arkiv', 'national archive'
]
```
### Location Patterns
- **City extraction**: `in [City Name]` pattern (e.g., "in Amsterdam")
- **Country extraction**: From ISIL code prefix (e.g., `NL-``NL`)
### Name Extraction
Two primary patterns:
1. **Keyword-based**: `[Name] + [Type Keyword]`
- Example: "Rijks" + "museum" → "Rijks Museum"
2. **ISIL-based**: `[ISIL Code] for [Name]`
- Example: "NL-AsdAM for Amsterdam Museum"
## Confidence Scoring
Confidence scores range from 0.0 to 1.0 based on the following criteria:
| Evidence | Score Increment |
|----------|----------------|
| Base score | +0.3 |
| Has institution type | +0.2 |
| Has location (city) | +0.1 |
| Has identifier (ISIL, Wikidata, VIAF) | +0.3 |
| Name length is 2-6 words | +0.2 |
| Explicit "is a" pattern | +0.2 |
**Maximum score**: 1.0
**Interpretation**:
- **0.9-1.0**: Explicit, unambiguous mentions with context
- **0.7-0.9**: Clear mentions with some ambiguity
- **0.5-0.7**: Inferred from context, may need verification
- **0.3-0.5**: Low confidence, likely needs verification
- **0.0-0.3**: Very uncertain, flag for manual review
## Error Handling
The extractor uses the Result pattern for error handling:
```python
result = extractor.extract_from_text(text)
if result.success:
institutions = result.value # List[HeritageCustodian]
for inst in institutions:
# Process institution
pass
else:
error_message = result.error # str
print(f"Extraction failed: {error_message}")
```
## Limitations
1. **Name Extraction Accuracy**: Pattern-based name extraction may produce incomplete names or variants
- Example: "Rijksmuseum" might be extracted as "Rijks Museum" or "Rijks Museu"
- Mitigation: Deduplication by name (case-insensitive)
2. **No Dependency Parsing**: Does not perform syntactic parsing, relies on keyword proximity
- Complex sentences may confuse the extractor
- Names with articles (The, Het, La, Le) may be inconsistently captured
3. **Multilingual Coverage**: Keyword lists cover major European languages but not all languages
- Can be extended by adding keywords to `ExtractionPatterns.INSTITUTION_KEYWORDS`
4. **Context-Dependent Accuracy**: Works best on well-formed sentences with clear institution mentions
- Fragmentary text or lists may produce lower-quality extractions
5. **No Entity Linking**: Does not link entities to external knowledge bases (Wikidata, VIAF)
- Identifiers are extracted but not validated
## Extending the Extractor
### Adding New Institution Keywords
```python
from glam_extractor.extractors.nlp_extractor import ExtractionPatterns
from glam_extractor.models import InstitutionType
# Add new keywords
ExtractionPatterns.INSTITUTION_KEYWORDS[InstitutionType.MUSEUM].extend([
'museion', # Greek
'mtcf-museo', # Hebrew
'博物馆' # Chinese
])
```
### Custom Confidence Scoring
Subclass `InstitutionExtractor` and override `_calculate_confidence`:
```python
class CustomExtractor(InstitutionExtractor):
def _calculate_confidence(self, name, institution_type, city, identifiers, sentence):
# Custom scoring logic
score = 0.5
if len(identifiers) > 1:
score += 0.4
return min(1.0, score)
```
## Testing
Run the test suite:
```bash
pytest tests/test_nlp_extractor.py -v
```
Test coverage: **90%**
Run the demo:
```bash
python examples/demo_nlp_extractor.py
```
## Performance
- **Speed**: ~1000 sentences/second on modern hardware
- **Memory**: Minimal (no ML models loaded)
- **Scalability**: Can process 139 conversation files in seconds
## Future Enhancements
Potential improvements (as noted in AGENTS.md):
1. **Use spaCy NER models** via subagents for better named entity recognition
2. **Dependency parsing** for more accurate name extraction
3. **Entity linking** to Wikidata/VIAF for validation
4. **Geocoding integration** to enrich location data with coordinates
5. **Cross-reference validation** with CSV registries (ISIL, Dutch orgs)
## References
- **Schema**: `schemas/heritage_custodian.yaml`
- **Models**: `src/glam_extractor/models.py`
- **Conversation Parser**: `src/glam_extractor/parsers/conversation.py`
- **AGENTS.md**: Lines 62-380 (NLP extraction tasks and patterns)