Data Model – Entity Definitions

This page defines the principal entities used in the 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 are conceptual. They describe meaning and intent, not database or software mechanics.

Scope

These definitions apply to:

Conceptual ER modeling
Future Cargo table design
Page Schemas and forms
Editorial workflows
Interpretation of diagrams and documentation

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

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 historically meaningful place (e.g. “Historical Ostend”)
A functional or conceptual part of a larger entity (e.g. “Medical practice in a 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 technical 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 earlier notions of object sets or collections.

Relationship to Digital Assets

A HeritageObject:

May be linked to multiple DigitalAssets
May designate one DigitalAsset as the preferred representation

Multiplicity and representational choice are managed at the HeritageObject level.

Purpose

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

DigitalAsset (DA)

Definition

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

It answers the question:

“How do we interpret and describe this specific digital file?”

A DigitalAsset can be understood as the human, research-oriented layer that gives meaning to a file.

Core principle

One DigitalAsset corresponds to exactly one File.

There is no grouping of multiple files inside a single DigitalAsset.

Examples

A DigitalAsset may represent:

A photograph file and its interpretation
A scanned document file
An OCR-generated PDF file
A cropped or processed derivative of another file

Each of these is a separate DigitalAsset if it is a separate file.

Relationship to Files

A DigitalAsset:

Always references exactly one File
Does not manage file storage
Does not replace MediaWiki file handling

Files are managed entirely by MediaWiki. DigitalAssets describe and interpret them.

Recursive behavior

DigitalAssets are recursive.

A DigitalAsset may:

Have a parent DigitalAsset (e.g. original → derivative)
Have zero or more child DigitalAssets

Recursion is used to model:

Variants
Derivatives
Processing steps
Interpretative lineage

Relationship to HeritageObjects

A DigitalAsset:

Is linked to one or more HeritageObjects
Always attaches to the most specific relevant HeritageObject

A HeritageObject may reference many DigitalAssets, but each DigitalAsset interprets only one file.

What a DigitalAsset is not

A DigitalAsset is:

Not a file
Not a container of multiple files
Not a public-facing object by default
Not a historical object itself

Purpose

DigitalAssets exist to:

Separate meaning from storage
Provide rich, research-oriented metadata
Record provenance, role, and certainty
Support controlled selection of representations

File (External System Entity)

Definition

A File is a physical digital object managed by MediaWiki.

Examples include:

Image files
Scanned documents
PDFs
Other uploaded media

Modeling status

Files are:

Not owned by the data model
Not defined conceptually within the research domain
Included in diagrams only as external reference entities

File lifecycle, storage, and technical metadata are fully managed by MediaWiki.

Relationship to Digital Assets

Each File:

Is referenced by exactly one DigitalAsset
Has meaning in the project only through its DigitalAsset

Files are storage. DigitalAssets are interpretation.

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 historically?”

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

All such relationships are qualified by:

Role
Certainty

Purpose

Actors model historical agency, responsibility, and influence.

Organization

Definition

An Organization represents a historical collective actor.

Examples include:

Religious congregations
Institutions
Associations
Managing bodies

What an Organization is not

An Organization is:

Not a person
Not a HeritageObject
Not a MediaWiki group

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?”

Characteristics

A ResearchChapter:

Is not merely a date range
Reflects interpretation and structure
May overlap with other chapters

Relationships

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

Purpose

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

Certainty

Definition

Certainty expresses 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

Important note

Certainty is:

Not a property of an entity itself
Always attached to a statement or relationship

Purpose

Certainty makes interpretation explicit and avoids false precision.

Status

This document defines the current, agreed-upon conceptual meaning of the entities.

The ER model and all implementation work must conform to these definitions.