Data Model – Entity Definitions

This page defines the principal conceptual entities of the project.

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 responsibility, not database tables, Cargo structures, or software mechanics.

Scope

These definitions apply to:

Conceptual ER modeling
Cargo or database 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 distinguishes clearly between:

Storage → Files
Interpretation of files → DigitalAssets
Subjects of research → HeritageObjects, Persons, Organizations
Narrative structure → ResearchChapters

The fundamental semantic flow is:

File → DigitalAsset → Research Entity

DigitalAssets provide meaning to files. Research entities provide historical meaning to DigitalAssets.

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 sanatorium
A building
A historically meaningful place
A document or register
A functional or conceptual part of a larger entity (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

This supports conceptual decomposition.

Example:

Sanatorium
- Architecture
- Equipment
- Medical practice

Relationships

A HeritageObject may:

Be documented by multiple DigitalAssets
Be linked to Persons with roles
Be linked to Organizations with roles
Have Persons or Organizations as holders
Be included in multiple ResearchChapters
Be tagged with Keywords

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

Sister Maria
A director
An architect
A patient
A shareholder

What a Person is not

A Person is:

Not a MediaWiki user
Not a HeritageObject
Not an organization

Relationships

A Person may:

Play roles in relation to HeritageObjects
Play roles in relation to Organizations
Be documented by DigitalAssets (photos, documents, biographies)
Act as a holder of HeritageObjects

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
Institutions
Associations
Managing bodies

What an Organization is not

An Organization is:

Not a person
Not a HeritageObject
Not a MediaWiki user group

Relationships

An Organization may:

Play roles in relation to HeritageObjects
Have Persons playing roles within it
Be documented by DigitalAssets (articles, reports, archival documents)
Act as a holder of HeritageObjects

Purpose

Organizations model collective responsibility and institutional continuity.

Digital Representation

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 source?”

A DigitalAsset is the human, research-oriented 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 photograph and its description
A scanned document
An OCR transcription
A cropped or processed derivative
A newspaper article scan
A portrait of a person

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 (parent)
Have multiple derived children

This models:

variants
processing steps
derivatives
provenance chains

Relationship to research entities

A DigitalAsset may document one or more:

HeritageObjects
Persons
Organizations

DigitalAssets represent sources about research subjects.

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
Record provenance
Link sources to research subjects

File (External System Entity)

Definition

A File is a physical digital object managed by MediaWiki.

Examples include:

images
scans
PDFs
audio or video files

Modeling status

Files are:

Outside the conceptual research domain
Managed entirely by MediaWiki
Included only as external reference entities

Files provide storage only. They gain research meaning only through a DigitalAsset.

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

Structural behavior

ResearchChapters are recursive.

A Chapter may contain subchapters.

Top levels often represent time slices. Lower levels often represent themes.

Time is descriptive, not defining.

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 are attributes of relationships, not of entities themselves.

Certainty (future extension)

Certainty expresses confidence in an assertion.

It qualifies statements such as:

roles
attributions
dates
interpretations

Certainty is attached to relationships or claims, never to entities.

This concept is reserved for later implementation.

Status

This document defines the agreed conceptual meaning of the entities – Version 3.1.

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