Tagtriples Model and Semantics

Basics

Tagtriples metadata consists of 'statements', each containing 3 symbols - a 'subject', a 'property' and an 'object' symbol. E.g.:

PhilDawes type Person
PhilDawes hairColour Brown
PhilDawes plays FrenchHorn

An ordered collection of statements (e.g. from a document) is called a 'graph'.

Semantics

Graphs

All occurances of a particular symbol in a graph must denote the same meaning. The only exception to this is when the symbol is suffixed with a usage id. E.g. the following represents three different 'Sleeper's in the same graph.

Sleeper description 'A railway thingy'
Sleeper[2] description 'A dormant spy'
Sleeper[3] description 'Somebody who sleeps'

A symbol with no explicit usage suffix has an implicit usage id of '0'

N.B. The same symbol used in different graphs may or may not denote the same meaning - it is up to the consumer of the information to interpret how the symbol/meanings correspond.

Ordering

The order of statements in a graph has significance. E.g. a client retrieving a graph from a store can expect the statements to come out in the same order as they went in.

The 'tag' symbol

There is a convention that the 'tag' symbol used as a predicate denotes that the object may be used to classify the subject in some way.

Fred tag dog
Sleeper tag 'Railway Sleeper'
Sleeper[2] tag spy
Sleeper[3] tag sleeping

E.g. when converting RDF to tagtriples, my import software tags symbols with their corresponding RDF URIs.

PhilDawes name 'Phil Dawes'
name tag 'http://xmlns.com/foaf/0.1/'

Phil Dawes

Last modified: Mon Aug 22 09:17:41 BST 2005