Data Model – Entity Definitions

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
Narrative structure → ResearchChapters

The fundamental conceptual flow is:

File → DigitalAsset → Research Entity

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

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

This supports conceptual decomposition and hierarchical structuring.

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

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 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)

Purpose

Organizations model collective responsibility and institutional continuity.

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

DigitalAssets therefore function as research sources.

Publication and citation role

DigitalAssets may additionally store:

bibliographic citation text
repository information
permalinks
rights information
publication suitability

Public pages cite DigitalAssets as sources and may display their associated files as illustrations.

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.

Modeling status

Files are:

external to the conceptual research domain
managed entirely by MediaWiki
included only as reference entities

Files 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.

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

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

Descriptive explanation is preferred.

How uncertainty is expressed

Use:

precise wording
ranges or approximate values
explicit notes
citations to DigitalAssets

Example:

"mentioned only once in a newspaper article"

is preferred over

"certainty = low".

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 3.2.

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