# Ontology Mapping Rules - Quick Reference

**Created**: 2025-11-20  
**Purpose**: Summary of critical ontology engineering rules for heritage custodian project

---

## Key Changes Made

### 1. Updated AGENTS.md
Added **PROJECT CORE MISSION** section at top emphasizing:
- This is an **ontology engineering project**, not simple data extraction
- Multi-aspect temporal modeling is required
- Multiple base ontologies must be integrated
- Wikidata entities are NOT ontology classes

### 2. Created .opencode/agent/ontology-mapping-rules.md
Comprehensive 30-page guide covering:
- Ontology consultation workflows
- Wikidata entity mapping procedures
- Multi-aspect modeling requirements
- Temporal independence documentation
- Property research workflows
- Decision trees for ontology selection
- Quality assurance checklists

---

## Core Principles

### Principle 1: Ontology Files Are Source of Truth
**ALWAYS** read base ontologies before designing:
```bash
# Example: Research CIDOC-CRM for heritage sites
rg "E27_Site|E53_Place" /Users/kempersc/apps/glam/data/ontology/CIDOC_CRM_v7.1.3.rdf
```

### Principle 2: Wikidata ≠ Ontology
**NEVER** use Wikidata Q-numbers as `class_uri`:
```yaml
❌ WRONG: class_uri: wd:Q1802963
✅ RIGHT: class_uri: crm:E27_Site  # After mapping Q1802963 to ontology
```

### Principle 3: Multi-Aspect Modeling
**EVERY** heritage entity has multiple aspects:
- **Place** (construction → present)
- **Custodian** (founding → present)
- **Legal form** (registration → present)
- **Collections** (accession → present)
- **People** (employment periods)
- **Events** (custody transfers, mergers)

### Principle 4: Temporal Independence
**Each aspect has its OWN timeline:**
```yaml
# Building exists 1880-present (144 years)
place_aspect:
  temporal_extent:
    start_date: "1880-01-01"
    end_date: null

# Museum organization founded 1994-present (30 years)
custodian_aspect:
  temporal_extent:
    start_date: "1994-05-12"
    end_date: null
```

---

## Available Ontologies

| Ontology | File | Use For |
|----------|------|---------|
| **CPOV** | `core-public-organisation-ap.ttl` | EU public sector heritage |
| **TOOI** | `tooiont.ttl` | Dutch government organizations |
| **Schema.org** | `schemaorg.owl` | Web semantics, private sector |
| **CIDOC-CRM** | `CIDOC_CRM_v7.1.3.rdf` | Cultural heritage domain |
| **RiC-O** | `RiC-O_1-1.rdf` | Archival description |
| **BIBFRAME** | `bibframe_vocabulary.rdf` | Library collections |
| **PiCo** | `pico.ttl` | Person observations, staff roles |

---

## Required Workflow

```
1. Read hyponyms_curated.yaml (Wikidata entities)
       ↓
2. Analyze hypernym + semantic properties
       ↓
3. Search base ontologies for matching classes
       ↓
4. Map Wikidata entity → Ontology class(es)
       ↓
5. Extract relevant properties from ontologies
       ↓
6. Document rationale and temporal model
       ↓
7. Create LinkML schema with class_uri
       ↓
8. Human review if complexity ≥ 7/10
```

---

## Example: Mansion (Q1802963)

### ❌ Wrong Approach
```yaml
Mansion:
  class_uri: wd:Q1802963  # Wikidata entity used directly
```

### ✅ Correct Approach
```yaml
Mansion:
  wikidata_source: Q1802963
  
  # PLACE ASPECT
  place_aspect:
    class_uri: crm:E27_Site  # CIDOC-CRM
    secondary_class_uri: schema:LandmarksOrHistoricalBuildings
    temporal_extent:
      start_date: "1880-01-01"  # Construction
  
  # CUSTODIAN ASPECT (if operates as museum)
  custodian_aspect:
    class_uri: cpov:PublicOrganisation  # If public
    alt_class_uri: schema:Museum  # If private
    temporal_extent:
      start_date: "1994-05-12"  # Foundation established
  
  # COLLECTIONS ASPECT
  collections_aspect:
    class_uri: crm:E78_Curated_Holding
    temporal_extent:
      start_date: "1994-01-01"  # Accessions begin
```

---

## Decision Tree: Ontology Selection

```
Is it Dutch government?
  ├─ YES → tooi:Overheidsorganisatie + cpov:PublicOrganisation
  └─ NO → Is it public sector?
           ├─ YES → cpov:PublicOrganisation
           └─ NO → schema:Organization
                    ├─ Museum → schema:Museum
                    ├─ Archive → schema:ArchiveOrganization
                    ├─ Library → schema:Library
                    └─ NGO → schema:NGO

Is it a physical site?
  ├─ YES → crm:E27_Site + schema:Place
  └─ NO → Continue with organizational classes

Does it hold collections?
  ├─ Archival → rico:RecordSet
  ├─ Museum → crm:E78_Curated_Holding
  └─ Library → bf:Collection

Does it have staff?
  └─ YES → pico:PersonObservation + crm:E21_Person
```

---

## Quality Checklist

Before submitting ontology design:

- [ ] Base ontologies consulted (`/data/ontology/` files read)
- [ ] Wikidata entities mapped (not used directly as classes)
- [ ] Multi-aspect modeling applied
- [ ] Temporal independence documented
- [ ] Properties sourced from ontologies
- [ ] Rationale documented
- [ ] Examples provided
- [ ] Complexity score assigned (1-10)
- [ ] Human review requested if complexity ≥ 7

---

## Files Updated

1. **AGENTS.md** - Added PROJECT CORE MISSION section (lines 1-100)
2. **.opencode/agent/ontology-mapping-rules.md** - NEW comprehensive guide
3. **This file** (ONTOLOGY_RULES_SUMMARY.md) - Quick reference

---

## Next Steps

1. Continue manual ontology mapping for hyponyms_curated.yaml entries
2. Document each mapping with full rationale
3. Build aspect-based LinkML schema modules
4. Create temporal modeling examples for common patterns

---

## Key Resources

- **Full Rules**: `.opencode/agent/ontology-mapping-rules.md`
- **Agent Instructions**: `AGENTS.md`
- **Ontology Files**: `data/ontology/`
- **Wikidata Sources**: `data/wikidata/GLAMORCUBEPSXHFN/`

**Remember**: This is ontology engineering, not data extraction. Precision matters more than speed.