ICT:Data Model Entity Definitions - v 4.0

Data Model – Entity Definitions version 4.0

This page defines the principal conceptual entities used in the project’s data model.

Its purpose is to establish a shared and explicit understanding of what each entity represents before any technical implementation is undertaken.

These definitions describe meaning and responsibility, not database structure or software mechanics.

Scope

These definitions guide:

• conceptual ER modeling
• DBML and Cargo schemas
• Page Schemas and forms
• editorial workflows
• interpretation of diagrams and documentation

If an entity definition is unclear or disputed, implementation must be postponed.

Conceptual overview

The model separates clearly between:

• Storage → Files
• Interpretation of files / sources → DigitalAssets
• Subjects of research → HeritageObjects, Persons, Organizations
• Spatial context → Places
• Narrative structure → ResearchChapters

The fundamental conceptual flow is:

File → DigitalAsset → Research Entity → Place

Files provide storage. DigitalAssets provide interpretation and source metadata. Research entities provide historical meaning. Places provide spatial context.

This separation prevents semantic confusion and keeps responsibilities explicit.

Core Research Entities

HeritageObject (HO)

Definition

A HeritageObject (HO) represents a historical, conceptual, or material entity that is the subject of study.

It answers the question:

“What is the thing we are studying?”

Examples

A HeritageObject may represent:

• a sanatorium
• a building
• a document or register
• a historically meaningful place
• a room, component, or architectural element
• a conceptual or functional unit (e.g. “medical practice”)

What a HeritageObject is not

A HeritageObject is:

• not a digital file
• not a person
• not an organization
• not a research chapter
• not a technical database record

Structural behavior

HeritageObjects are recursive.

Each HeritageObject may:

• have zero or one parent HeritageObject
• have zero or more child HeritageObjects

Relationships

A HeritageObject may:

• be documented by multiple DigitalAssets
• designate one DigitalAsset as preferred representation
• be linked to Persons with roles
• be linked to Organizations with roles
• have Persons or Organizations as holders
• belong to multiple ResearchChapters
• be tagged with Keywords
• be associated with one or more Places

Purpose

HeritageObjects are the primary conceptual anchors of the research.

Person

Definition

A Person represents a historical individual with agency.

It answers the question:

“Who was involved historically?”

Examples

• religious sisters
• directors
• architects
• patients
• shareholders
• board members

What a Person is not

A Person is:

• not a MediaWiki user account
• not a HeritageObject
• not an organization

Relationships

A Person may:

• play roles in relation to HeritageObjects
• play roles within Organizations
• act as a holder of HeritageObjects
• be documented by DigitalAssets (portraits, letters, biographies, articles)

Roles belong to relationships, not to the Person entity itself.

Purpose

Persons model historical agency, responsibility, and participation.

Organization

Definition

An Organization represents a historical collective actor with institutional continuity.

It answers the question:

“Which collective body acted or was responsible?”

Examples

• religious congregations
• companies
• associations
• institutions
• managing bodies

What an Organization is not

An Organization is:

• not a person
• not a HeritageObject
• not a Place
• not a MediaWiki user group

Relationships

An Organization may:

• play roles in relation to HeritageObjects
• include Persons with roles
• act as holder of HeritageObjects
• be documented by DigitalAssets (reports, articles, archival material)
• be located in a Place

Purpose

Organizations model collective responsibility and institutional continuity.

Place

Definition

A Place represents a geographical or spatial location.

It answers the question:

“Where is or did this exist or occur?”

Places provide spatial context only and do not possess agency or responsibility.

Examples

A Place may represent:

• a city
• a village
• a building
• a site or complex
• a region or landscape
• a country
• a historically named or former location

What a Place is not

A Place is:

• not a person
• not an organization
• not a HeritageObject
• not an actor with responsibility

Places have no agency.

Collective or governing bodies must be modeled as Organizations.

Structural behavior

Places are recursive.

Each Place may:

• have zero or one parent Place
• have zero or more child Places

This supports geographic hierarchies.

Examples:

Room → Building → Site → City → Region → Country

Relationships

A Place may:

• locate Organizations
• locate HeritageObjects
• provide creation or depiction context for DigitalAssets

Purpose

Places:

• provide structured geographic information
• support querying and filtering by location
• prevent misuse of Organizations for spatial data
• avoid storing locations as free text
• enable future geographic extensions such as mapping or spatial search

Places separate where from who and what, preserving conceptual clarity.

Digital Representation and Sources

DigitalAsset (DA)

Definition

A DigitalAsset (DA) represents the research interpretation and extended metadata of exactly one digital file.

It answers the question:

“How do we interpret and describe this specific digital file as a research source?”

A DigitalAsset is the human, scholarly layer that gives meaning to a file.

Core principle

One DigitalAsset corresponds to exactly one File.

There is never a grouping of multiple files inside one DigitalAsset.

Each file that requires interpretation has its own DigitalAsset.

Examples

A DigitalAsset may represent:

• a photograph
• a scanned document
• an OCR transcription
• a cropped derivative
• a newspaper article
• a portrait
• a letter or archival record

Relationship to Files

A DigitalAsset:

• always references exactly one File
• does not manage storage
• does not replace MediaWiki file handling

Files are storage. DigitalAssets are interpretation.

Recursive behavior

DigitalAssets are recursive.

A DigitalAsset may:

• derive from another DigitalAsset
• have multiple derived children

This models provenance and processing chains.

Relationship to research entities

A DigitalAsset may document one or more:

• HeritageObjects
• Persons
• Organizations

Spatial context

A DigitalAsset may optionally reference a Place to record:

• place of creation
• place depicted
• place of discovery
• or other relevant spatial association

Publication and citation role

DigitalAssets may additionally store:

• bibliographic citation text
• repository information
• permalinks
• rights information
• publication suitability

What a DigitalAsset is not

A DigitalAsset is:

• not a file
• not a container of files
• not a historical object itself
• not merely technical metadata

Purpose

DigitalAssets exist to:

• separate meaning from storage
• provide rich research metadata
• document provenance
• serve as scholarly sources
• support referencing and citation

File (External System Entity)

Definition

A File is a physical digital object managed by MediaWiki.

Files are external to the conceptual research domain and provide storage only.

They gain research meaning only through DigitalAssets.

Research Structure

ResearchChapter

Definition

A ResearchChapter represents a conceptual or narrative unit of interpretation.

It answers the question:

“Where does this belong in the research story?”

Characteristics

A ResearchChapter:

• structures interpretation
• is not merely a date range
• may be thematic or chronological
• may overlap with other chapters

Structural behavior

ResearchChapters are recursive.

Chapters may contain subchapters.

Relationships

• a Chapter may include multiple HeritageObjects
• a HeritageObject may belong to multiple Chapters

Purpose

ResearchChapters organize interpretation rather than historical reality itself.

Supporting Concepts

Keywords

Keywords provide flexible thematic tagging.

They support discovery but do not define structure.

Roles

Roles qualify relationships between entities.

Examples:

• creator
• owner
• restorer
• shareholder
• board member
• holder

Roles belong to relationships, not to entities themselves.

Treatment of Uncertainty (Certainty)

Conceptual position

Uncertainty is inherent in historical research.

Many statements involve approximation or interpretation.

Design decision

The data model deliberately does NOT implement:

• certainty entities
• confidence scores
• high/medium/low levels
• probability flags

Uncertainty is not stored structurally.

Rationale

Formal certainty levels:

• create false precision
• oversimplify interpretation
• increase editorial burden
• convey less information than descriptive notes

How uncertainty is expressed

Use:

• precise wording
• ranges or approximate values
• explicit notes
• citations to DigitalAssets

Future extension

Structured certainty may be added only if clear analytical needs arise.

Until then, descriptive practice remains the standard.

Status

This document defines the agreed conceptual meaning of the entities – Version 4.0.

All ER diagrams, DBML definitions, schemas, and implementations must conform to these definitions.