# OpenStreetMap Enrichment Report

**Date**: 2025-11-06  
**Dataset**: Latin American GLAM Institutions  
**Phase**: 5 - OpenStreetMap Enrichment

## Executive Summary

Successfully enriched **83 out of 186 institutions** (44.6%) with OpenStreetMap data, adding precise coordinates, street addresses, contact information, opening hours, and alternative names.

## Processing Statistics

- **Total institutions processed**: 304
- **Institutions with OSM IDs**: 186 (61.2%)
- **OSM records successfully fetched**: 152 (81.7% fetch success rate)
- **Institutions enriched**: 83 (44.6% enrichment rate)
- **OSM fetch errors**: 34 (18.3%)

## Enrichment Breakdown

| Enrichment Type | Count | Description |
|---|---|---|
| **Street addresses** | 33 | Added detailed street addresses from addr:street and addr:housenumber tags |
| **Contact information** | 19 | Added phone numbers and/or email addresses |
| **Websites** | 16 | Added institutional website URLs |
| **Alternative names** | 13 | Added alternative, official, or multilingual names |
| **Opening hours** | 10 | Added opening hours information |

## Data Quality

### Fetch Success Rate by Country

The OSM enrichment relied on the Overpass API, which experienced:
- **504 Gateway Timeout errors**: Server overload during peak processing
- **429 Rate Limiting errors**: Managed through 3-second delays and retry logic
- **Overall fetch success**: 152/186 = 81.7%

### Enrichment Quality

Enriched data includes:
1. **Precise coordinates**: Building-level accuracy from OSM nodes/ways
2. **Structured addresses**: Street names, house numbers, postal codes
3. **Verified contact info**: Phone/email from OSM contributors
4. **Operating hours**: Opening hours in OSM standard format
5. **Multilingual names**: Alternative names in English, Spanish, Portuguese

All enrichments are tracked in provenance notes with timestamps and sources.

## Technical Implementation

### Scripts Created

1. **`scripts/enrich_from_osm.py`** (569 lines)
   - Original implementation with retry logic
   - Rate limiting: 2 seconds between requests
   - Timeout handling with exponential backoff

2. **`scripts/enrich_from_osm_batched.py`** (452 lines)
   - Batch processing (20 institutions per batch)
   - Incremental progress saving
   - Resilient to timeouts

3. **`scripts/resume_osm_enrichment.py`** (365 lines)
   - Resume from institution 101
   - Extended rate limiting (3 seconds)
   - Completed remaining 204 institutions

### Overpass API Configuration

- **Primary endpoint**: `https://overpass-api.de/api/interpreter`
- **Mirror failover**: Kumi Systems, OpenStreetMap Russia
- **Query timeout**: 30 seconds
- **Rate limiting**: 2-3 seconds between requests
- **Retry logic**: Max 3 attempts with 10-second delays

## Example Enrichments

### Museu Sacaca (Amapá, Brazil)
- **Added**: Street address (Avenida Feliciano Coelho 1502)
- **Added**: Postal code
- **Added**: Website

### Teatro da Paz (Pará, Brazil)
- **Added**: Full street address
- **Added**: Phone (+55 91 98590-3523)
- **Added**: Website
- **Added**: 2 alternative names

### Universidade Federal do Piauí
- **Added**: Coordinates (building-level precision)
- **Added**: Complete address
- **Added**: Phone and email
- **Added**: Website
- **Added**: Opening hours

## Output Files

- **Primary output**: `data/instances/latin_american_institutions_osm_enriched.yaml` (456 KB)
- **Processing log**: `osm_resume_log.txt`
- **This report**: `docs/osm_enrichment_report.md`

## Next Steps

1. **Generate exports**: JSON-LD, CSV, GeoJSON for geographic visualization
2. **Update PROGRESS.md**: Document Phase 4-5 findings
3. **Manual review**: Verify enrichment quality for high-value institutions
4. **National library outreach**: Send emails to request ISIL codes

## Known Issues

1. **VIAF API unavailable**: All 19 VIAF IDs return HTTP 404 (documented separately)
2. **Partial OSM coverage**: Only 44.6% of institutions with OSM IDs were enriched
   - Reasons: Missing tags in OSM, no building-level data, fetch errors
3. **Coordinate precision**: Not all OSM records improved coordinate precision
   - OSM city-level nodes don't improve existing city-level coordinates

## Conclusion

The OSM enrichment successfully added valuable metadata to 83 institutions, improving data quality with verified street addresses, contact information, and precise geographic coordinates. The 44.6% enrichment rate reflects the reality that many heritage institutions lack detailed tagging in OpenStreetMap, highlighting an opportunity for future crowdsourced contributions.

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**Report generated**: 2025-11-06  
**Author**: Global GLAM Dataset Project