Metadata

Collection Level Description

Collection entity relationships

The diagram below shows the primary entity relationships for collections, items, agents and terms & conditions.

Entity-relationship diagram

Entities

Collection
A group of items or other collections. See the enumerated list of collection types for examples of collections.
Item
An individual object. For example a Web page, an image, a audio file, a dataset, a book, a manuscript, a museum artefact or a piece of software. Often refered to as a 'resource'. Note that items may be composed of multiple other items - the dividing line between items and collections is therefore somewhat fuzzy.
Agent
A person or organisation.
Application
A piece of software that implements an access protocol. For example a Web, Z39.50, LDAP or Whois++ server.
*** Also need to include physical access here somehow???
Terms & Conditions
May include: These may be associated with:

Relationships

HasPart/IsPartOf
Relationships in which one collection or item is a physical or logical part of another.
IsCataloguedBy/IsCatalogueFor
Relationships in which one collection is the catalogue for, or contains a catalogue record for, another.
Owner
The relationship between a collection and the agent that owns it.
Admin
The relation between an application and the 'service provider' (or 'resource operator'?) that manages it.
Publisher
The relationship between an application and the entity responsible for making it available in its present form.
*** Application or collection ???
Access
The relationship between a collection and an application that provides access to it.
Term
The relationship between an application, a collection or an item and a set of terms & conditions. In real systems this relationship may be dependant on the 'end-user' (agent) as well.
Maintained by: Andy Powell
Last updated: 14-Oct-1998

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