Conceptual Definitions of Principal Entities

This page defines the meaning of the principal entities used in the data model.

Its purpose is to ensure a shared understanding of each entity before finalizing the ER model and starting any technical implementation.

The definitions are conceptual, not technical, and should be read as design intent rather than database specification.

Scope

These definitions apply to:

Conceptual ER modeling
Future Cargo table design
Page Schemas and forms
Editorial workflows

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

HeritageObject (HO)

Definition

A HeritageObject (HO) represents a historical, conceptual, or material entity that is relevant to the research subject and has meaning in its own right, independent of how it is documented.

It answers the question:

“What is the thing we are studying?”

Examples

A HeritageObject may represent:

A sanatorium
A building
A historically meaningful place (e.g. “Historical Ostend”)
A functional or conceptual component of a larger entity (e.g. “Medical practice in the sanatorium”)

What a HeritageObject is not

A HeritageObject is:

Not a digital file
Not a person
Not an organization
Not a research chapter
Not a database record

Structural behavior

HeritageObjects are recursive.

Each HeritageObject may:

Have zero or one parent HeritageObject
Have zero or more child HeritageObjects

This supports conceptual decomposition, for example:

Sanatorium Ostend
- External architecture
- Internal organization
- Medical practice

This structure replaces former notions of object sets or collections.

Purpose

HeritageObject is the central anchor of the model. All other entities ultimately relate to one or more HeritageObjects.

DigitalAsset (DA)

Definition

A DigitalAsset (DA) represents a curated, semantic representation of something, usually a HeritageObject or part of it.

It answers the question:

“What digital material do we have that represents or documents something?”

Examples

A DigitalAsset may represent:

A photograph (as a concept)
A scan of a document
A map
A plan or drawing
A group of related digital derivatives

What a DigitalAsset is not

A DigitalAsset is:

Not a file
Not a HeritageObject
Not public-facing content by default

Relationship to files

A DigitalAsset may reference:

One or more files in the File: namespace
Multiple formats or derivatives of the same material

Example:

One DigitalAsset → TIFF master + JPG derivative + OCR PDF

Files may change over time while the DigitalAsset remains stable.

Structural behavior

A DigitalAsset:

May have a parent DigitalAsset (derivative relationship)
May be linked to one or more HeritageObjects
Is attached to the most specific relevant HeritageObject

Purpose

DigitalAssets exist to:

Separate meaning from storage
Group files meaningfully
Support derivatives and versions
Manage publication decisions
Document provenance

Actor (Historical Person)

Definition

An Actor represents a historical person involved in the subject matter of the research.

It answers the question:

“Who was involved in this historically?”

Examples

Actors may include:

Doctors
Directors
Religious figures
Other identifiable historical individuals

What an Actor is not

An Actor is:

Not a MediaWiki user account
Not a HeritageObject
Not an organization

Relationships

An Actor may:

Play roles in relation to HeritageObjects
Belong to Organizations
Have relationships with other Actors (e.g. family, succession)

All such relationships are explicitly described and qualified by:

Role
Certainty

Purpose

Actors model historical agency, responsibility, authorship, and influence.

Organization

Definition

An Organization represents a historical collective actor.

It answers the question:

“Which institution or group acted as a unit in history?”

Examples

Organizations may include:

Religious congregations
Associations
Institutions
Managing bodies of sanatoria

What an Organization is not

An Organization is:

Not a person
Not a HeritageObject
Not a MediaWiki group

Relationships

An Organization may:

Be related to HeritageObjects (e.g. ownership, management)
Have members (Actors)
Play roles over time

Purpose

Organizations allow modeling of institutional continuity and collective action.

ResearchChapter (or Period)

Definition

A ResearchChapter represents a conceptual or narrative unit of the research.

It answers the question:

“In which phase or thematic period does this belong in the research story?”

Examples

ResearchChapters may include:

Initial ideas and congresses
Berck-sur-Mer experiments
First Belgian coastal sanatoria
Delcroix family generations

What a ResearchChapter is not

A ResearchChapter is:

Not merely a date range
Not a HeritageObject
Not a place

Relationships

A ResearchChapter may include multiple HeritageObjects
A HeritageObject may belong to multiple ResearchChapters

Purpose

ResearchChapters model interpretation and narrative structure rather than historical reality itself.

Place (Modeling Rule)

Definition

A Place is modeled explicitly only when it is itself an object of historical study.

Rule

Historically meaningful places → modeled as HeritageObjects
Pure geographic information → modeled as attributes

Example:

“Historical Ostend” → HeritageObject
“City: Ostend” → attribute

Purpose

This allows places to:

Have DigitalAssets (maps, plans)
Evolve historically
Participate in research chapters

Certainty

Definition

Certainty represents the degree of confidence in an assertion.

It answers the question:

“How sure are we about this claim?”

Application

Certainty qualifies:

Relationships
Roles
Attributions
Dating
Interpretations

What Certainty is not

Certainty is:

Not a property of an entity itself
Not absolute truth

Purpose

Certainty makes interpretation explicit and avoids false precision.

Status

This document is a working conceptual glossary.

The ER model should not be finalized until these definitions are accepted and understood.