glam/FOUR_ASPECT_ARCHITECTURE_QUICK_REF.md

Four-Aspect Custodian Architecture - Quick Reference

Last Updated: 2025-11-22
Schema Version: 0.3.0

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Overview

Heritage custodian institutions are modeled as multi-aspect entities with four independent reconstruction outputs:

                        Custodian (hub)
                             │
            ┌────────────────┼────────────────┐
            │                │                │
    ┌───────▼────────┐  ┌────▼─────┐  ┌──────▼──────┐
    │ CustodianName  │  │Custodian │  │ Custodian   │
    │ (emic label)   │  │LegalStatus│  │   Place     │
    │                │  │(legal     │  │(nominal loc)│
    │ SKOS Concept   │  │entity)    │  │             │
    └────────────────┘  │           │  │CRM E53_Place│
                        │W3C ORG,   │  └─────────────┘
                        │TOOI, CPOV │
                        └───────────┘
                             │
                    ┌────────▼─────────┐
                    │CustodianCollection│
                    │(heritage materials)│
                    │                   │
                    │CRM E78, RiC-O,    │
                    │BIBFRAME           │
                    └───────────────────┘

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The Four Aspects

1. CustodianName (Emic Label)

Purpose: How heritage communities refer to the institution
Ontology: SKOS Concept
Key Property: skos:prefLabel

Characteristics:

• ✅ Ambiguous, contextual, vernacular
• ✅ Language-specific (multilingual support)
• ✅ Includes alternative names (skos:altLabel)
• ✅ Changes over time (name supersession)
• ❌ NOT a legal name (that's in LegalStatus)

Example:

preferred_label:
  emic_name: "Rijksmuseum"
  name_language: "nl"
  alternative_names:
    - "National Museum" (English)
    - "Rijks Museum" (variant spelling)

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2. CustodianLegalStatus (Legal Entity)

Purpose: Formal organizational entity with legal registration
Ontology: W3C ORG FormalOrganization, TOOI, CPOV
Key Property: org:hasRegisteredOrganization

Characteristics:

• ✅ Precise, registered, formal
• ✅ Includes legal form (ISO 20275 codes)
• ✅ Registration numbers (KvK, company numbers)
• ✅ Legal name (distinct from emic name)
• ✅ Hierarchical (parent/subsidiary relationships)

Example:

legal_status:
  legal_entity_type:
    code: "8100"  # ISO 20275: Central government
  legal_name:
    full_name: "Rijksmuseum Amsterdam"
  legal_form:
    elf_code: "NL-GOV"
    local_name: "Rijksoverheid agentschap"

---

3. CustodianPlace (Nominal Location)

Purpose: Where people say the institution "is"
Ontology: CIDOC-CRM E53_Place
Key Property: crm:P53_has_former_or_current_location

Characteristics:

• ✅ Nominal reference (NOT coordinates)
• ✅ Can be vague ("Amsterdam", not lat/lon)
• ✅ Linguistic/cultural (e.g., "Milano" vs "Milan")
• ✅ Changes over time (relocations)
• ❌ NOT a postal address (that's in LegalStatus)

Example:

place_designation:
  place_name: "Amsterdam"
  place_specificity: CITY
  place_note: "Museumstraat 1, 1071 XX"

---

4. CustodianCollection (Heritage Materials) ← NEW!

Purpose: Heritage materials managed by custodian (metonymic reference)
Ontology: CIDOC-CRM E78_Curated_Holding, RiC-O RecordSet, BIBFRAME Collection
Key Property: crm:P46_is_composed_of

Characteristics:

• ✅ Represents the "substance" of heritage work
• ✅ Multiple collection types (archival, museum, library)
• ✅ Independent lifecycle (materials span different time than custodian)
• ✅ Custody transfers (collections can move between custodians)
• ✅ Metonymic discourse ("The Rijksmuseum has a Rembrandt" = collection)

Example:

has_collection:
  - collection_name: "Rijksmuseum Collection"
    collection_type:
      - "museum_objects"
      - "library_holdings"
    temporal_coverage: "1100-2000"  # Materials span 9 centuries
    extent: "1 million objects"

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Why Four Aspects?

Independent Lifecycles

Each aspect can change independently without affecting others:

Event	Name	LegalStatus	Place	Collection
Name change	✓ Changes	Unchanged	Unchanged	Unchanged
Legal reorganization	Unchanged	✓ Changes	Unchanged	Unchanged
Relocation	Unchanged	Unchanged	✓ Changes	Unchanged
Custody transfer	Unchanged	Unchanged	Unchanged	✓ Changes
Merger	✓ May change	✓ Changes	✓ May change	✓ Collections merge

Example: Noord-Hollands Archief

• 2001 merger: Name changes, LegalStatus changes, Place changes (new building), Collections merge
• Tracking: Each aspect has valid_from/valid_to dates to model temporal changes

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Metonymic Discourse and Collection Aspect

What is Metonymy?

Using one entity (custodian) to refer to a related entity (collection).

Common Heritage Discourse:

• "The Rijksmuseum has a Rembrandt" → The collection contains it
• "The British Library digitized manuscripts" → The collection was digitized
• "The National Archives preserves colonial records" → The collection preserves them

Why Collections Need Separate Modeling

Before CustodianCollection, there was no way to model:

1. Collection identity - Collections have names distinct from custodians

   • Custodian: "Rijksmuseum"
   • Collection: "Rijksmuseum Collection" (general) + "Cuypers Library" (specific)

2. Multiple collections - One custodian can manage multiple collections

   • Rijksmuseum: Main museum collection + Cuypers Library + Asian Pavilion
   • British Library: General collection + Manuscripts + Sound Archive

3. Custody transfers - Collections move between custodians

   • Mondrian paintings moved from Museum Gemeente to Rijksmuseum
   • Colonial archives transferred from colonial offices to national archives

4. Joint custody - Multiple custodians can share management

   • Shared collections between state and municipal archives
   • Collaborative digital repositories

5. Collection-level provenance - Acquisition history distinct from custodian history

   • Custodian founded 1800
   • Collection materials span 1100-2000 (predates custodian by 700 years!)

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Slot Mapping Summary

CustodianName Slots (11)

• emic_name, name_language, standardized_name
• endorsement_source, name_authority
• alternative_names (→ CustodianAppellation)
• valid_from, valid_to
• supersedes, superseded_by
• refers_to_custodian

CustodianLegalStatus Slots (15+)

• legal_entity_type, legal_name, legal_form, legal_status
• registration_authority, registration_numbers
• governance_structure, parent_custodian
• identifiers (ISIL, KvK, etc.)
• dissolution_date, reconstruction_method
• temporal_extent, refers_to_custodian

CustodianPlace Slots (7)

• place_name, place_language
• place_specificity (CITY, REGION, COUNTRY, etc.)
• place_note
• valid_from, valid_to
• refers_to_custodian

CustodianCollection Slots (11) ← NEW!

• collection_name, collection_description
• collection_type (archival_records, museum_objects, etc.)
• collection_scope, temporal_coverage
• extent, arrangement_system, provenance_note
• valid_from, valid_to
• refers_to_custodian

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Collection Types Supported

Type	Ontology	Use Case
archival_records	rico:RecordSet	Government records, family papers, organizational archives
museum_objects	crm:E78_Curated_Holding	Paintings, sculptures, artifacts, decorative arts
library_holdings	bf:Collection	Books, serials, manuscripts, rare books
monuments	crm:E27_Site	Built heritage, archaeological sites
archaeological_materials	crm:E78_Curated_Holding	Excavation finds, assemblages
natural_history_specimens	crm:E78_Curated_Holding	Biological specimens, geological samples
digital_born	schema:Collection	Born-digital archives, web archives
photographs	crm:E78_Curated_Holding	Photographic collections
manuscripts	bf:Collection	Handwritten documents, medieval codices

Note: Collections can have multiple types (e.g., mixed archival + museum).

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Example: Complete Four-Aspect Record

Custodian:
  hc_id: https://nde.nl/ontology/hc/cust/rijksmuseum
  
  # Aspect 1: Name
  preferred_label:
    emic_name: "Rijksmuseum"
    name_language: "nl"
  
  # Aspect 2: Legal Status
  legal_status:
    legal_entity_type:
      code: "8100"  # Central government
    legal_name:
      full_name: "Rijksmuseum Amsterdam"
  
  # Aspect 3: Place
  place_designation:
    place_name: "Amsterdam"
    place_specificity: CITY
  
  # Aspect 4: Collection (NEW!)
  has_collection:
    - collection_name: "Rijksmuseum Collection"
      collection_type:
        - "museum_objects"
        - "library_holdings"
      temporal_coverage: "1100-2000"
      extent: "1 million objects"

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Ontology Alignment at a Glance

Aspect	Primary Ontology	Class URI
Name	SKOS	skos:Concept
LegalStatus	W3C ORG	org:FormalOrganization
Place	CIDOC-CRM	crm:E53_Place
Collection	CIDOC-CRM	crm:E78_Curated_Holding
	RiC-O	rico:RecordSet
	BIBFRAME	bf:Collection

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PiCo Observation/Reconstruction Pattern

All four aspects follow the PiCo-inspired pattern:

CustodianObservation (source data)
         ↓ prov:wasDerivedFrom
ReconstructionActivity (scholarly interpretation)
         ↓ prov:generated
CustodianName | CustodianLegalStatus | CustodianPlace | CustodianCollection
         ↓ prov:qualifiedAttribution
Custodian (hub - immutable URI)

Key Insight: The four aspects are reconstructed interpretations of source observations, not raw data.

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Implementation Checklist

When creating heritage custodian records, ensure:

• Custodian hub - Create unique hc_id URI
• CustodianName - Extract emic label with language
• CustodianLegalStatus - Document legal form and registration
• CustodianPlace - Record nominal location reference
• CustodianCollection - Model heritage materials ← NEW!
• CustodianObservation - Link each aspect to source observations
• ReconstructionActivity - Document scholarly method
• Temporal validity - Add valid_from/valid_to for all aspects
• Identifiers - Include ISIL, Wikidata, VIAF, URLs

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References

• Schema: schemas/20251121/linkml/01_custodian_name_modular.yaml
• Collection Class: schemas/20251121/linkml/modules/classes/CustodianCollection.yaml
• Example: schemas/20251121/examples/rijksmuseum_with_collection.yaml
• Full Documentation: CUSTODIAN_COLLECTION_ADDITION_20251122.md

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Key Takeaways

✅ Four aspects = Four independent lifecycles
✅ CustodianCollection = Metonymic discourse modeling
✅ Multiple collection types = Archival, museum, library support
✅ Custody transfers = Collections can move between custodians
✅ Temporal validity = Each aspect tracks its own valid_from/valid_to
✅ Ontology-aligned = Maps to CIDOC-CRM, RiC-O, BIBFRAME, SKOS, W3C ORG

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Quick Reference Version: 1.0
Generated: 2025-11-22T18:30:00Z