HeritageObject Type – Concept and Purpose

Why do we need a "Type" for HeritageObjects?

Each HeritageObject represents a physical or historical item such as:

church
bunker
farmhouse
bridge
lighthouse
monument
cemetery
windmill
etc.

These objects must be classified in a consistent way.

The field Type answers the simple question:

"What kind of object is this?"

Why not simply use free text?

A simple text field like:

type = church

looks easy but quickly creates problems.

Examples of inconsistent input:

church
Church
chapel
kerkje
small church

This causes:

spelling variations
duplicate meanings
impossible filtering
unreliable statistics
messy reports

Over time this becomes unmanageable.

The chosen solution

Instead of free text, we use a separate table:

HeritageObjectType

Relationship:

HeritageObject  →  HeritageObjectType

So every object selects its type from a predefined list.

Advantages of using a separate Type table

1. Consistency

Users must select from an existing list. No spelling errors or variations.

2. Reliable filtering

Examples:

show all bunkers
show all churches
count monuments per type

These queries become simple and accurate.

3. Statistics and reporting

Cargo queries can group by type:

number of churches
number of bridges
number of military objects

4. Extensibility

The type table can later store extra metadata:

description
icon
color
category
historical period
translations

Without changing the HeritageObject table.

5. Controlled vocabulary

The club agrees once on the official terminology.

Data model principle

This follows a standard database design rule:

Do not use free text for classification fields.

Instead:

Entity → Category/Type table

Other examples in this project:

Chapter hierarchy (parent chapter)
DigitalAssets linked to Chapter/Place/Organisation
HeritageObject linked to Type

This keeps the data clean and structured.

How it is implemented in MediaWiki

Namespace: HeritageObjectType
One page per type
Cargo table stores all types
Form uses a dropdown/combobox:

 values from namespace=HeritageObjectType

Users select a type instead of typing text.

Practical explanation for club members

If asked:

"What is Type for?"

Answer simply:

Type is the official category of the object (church, bunker, bridge, etc.) chosen from a list so everyone uses the same terminology.

Conclusion

The Type relation:

improves data quality
avoids ambiguity
enables statistics
supports future growth

It is therefore an essential part of the data model.