representing the structural elements of a freely faceted
TRANSCRIPT
Representing the structural elements
of a freely faceted classification
Claudio Gnoli (U Pavia)
Tom Pullman (U Cambridge)
Philippe Cousson (L Guérin, Poitiers)
Gabriele Merli (U Pavia)
Rick Szostak (U Alberta)
(ILC Project)
UDC Seminar 2011, The Hague
UDC Seminar 2009
Web-publish or perish !...
[Brickley, Soergel,
Dunshire, Binding, Isaac…]
…but in which format?
UNIMARC ? facets absent [Slavic & Cordeiro 2004; 2005]
SKOS ?
facets “postponed” [Miles 2008]
OWL 2 ? [Zeng et al. 2010]
Facet analysis
“the basis of all methods of IR”
[CRG 1955; Broughton 2006]
Available flavours:
common auxiliaries [DDC, classic UDC]
classic faceted classification [BC2, UDC revisions]
freely faceted classification [CRG, ILC project]
Freely faceted classification
Interdisciplinarity
laws : vessels : oceans : whales : conservation
laws ON conservation
conservation OF whales
whales IN oceans
vessels IN oceans
…
CRG-NATO draft scheme [1960s] V
ILC draft scheme [2004-2011-]
Development continues, but
a stable published edition is needed
for the sake of interoperability
Freely faceted classification
ILC 1
Published on the Web, 2011-07-15
www.iskoi.org/ilc/1/ilc.php
7052 classes,
browsable,
searchable
ILC developing version
www.iskoi.org/ilc/ilc.php
Yellow background
Also
browsable,
searchable
ILC database
Classification
Notational plane
Verbal plane
Idea plane
[Ranganathan]
knowledge representation
Freely faceted classification
Notational elements
Arrays, Chains, Deictics, Facets, Foci, Place of definition of foci, Examples of combinations, Subclasses of a faceted class, Groupings, Related classes
Verbal elements
Main caption, Synonyms, Descriptions, Included terms, Related terms, Notes
Arrays
Sensu Ranganathan Emptying digit z where >25 sister classes
Chains
m organisms
mq animals
mqv chordates
mqvt mammals
mqvtn whales
mqvtni dolphins
mqvtnis Stenella
Field for broader class in DBs for interoperability
Deictics
Ranganathan’s “favoured host class”
Extended in ILC
Facets etc.
Facet Place of definition of foci Caption Synonyms Description
Example of combination
nye estuaries
m8 [ny] organisms, adapted to habitat
m8e organisms, adapted to estuaries
Extra-defined focus (“parallel division” of a facet)
Subclass of a faceted class
The Genesis problem [Broughton 2010]
js6 landforms, modelled by agent
js6i landforms, modelled by wind
js6i:l loess
Relevant for common vs. civil law [Pullman p.c.]
Related classes
In ILC, only dependence relationships are recorded:
xxol alpinism « jsm mountains
Included terms
Related terms
In ILC, disciplines:
Dynamic Web interface
expander link to details depth selector
link to broader class
Representation in SKOS
mqvtn whales, cetaceans, cetacea
V ilc:mqvtn rdf:type skos:Concept;
skos:notation
"mqvtn"^^ilc:ILCNotation;
skos:broader ilc:mqvt;
skos:prefLabel "whales"@en;
skos:altLabel "cetaceans"@en;
skos:altLabel "cetacea"@en.
How to represent facets?
mqvtn2 [jU] whales, in area
V ilc:mqvtn2 rdf:type skos:Concept;
skos:notation "mqvtn2"^^ilc:ILCNotation;
skos:prefLabel "in"@en;
skos:altLabel "area"@en;
skos:broader ilc:mqvtn;
skos:broader ilc:2;
skos:related ilc:jU.
How to represent facets?
mqvtn2 [jU] whales, in area
skos:broader ilc:mqvtn;
skos:broader ilc:2;
Facets are “narrower terms” of both their basic class (mqvtn whales) and their fundamental category (2 in place)
Polyhierarchical model
mqvt 2
“mammals” “in place”
mqvtn2
“whales, in area ”
How to represent facets?
mqvtn2 [jU] whales, in area
skos:related ilc:jU
Facets can be described as “related terms” of their place of definition (jU regions)
but this is not an effective instruction. Some extension of skos:related seems to be needed
Clearly, these are but raw approximations
Alternative:
skos:collection
but conceived for node labels in thesauri,
not linkable to general categories
How to represent facets?
Facet combinations
Not to be all enumerated in SKOS
Possibly a converter ILC > SKOS (and back?) on demand
Other verbal terms
description + its synonyms ~ skos:note
+ related discipline
included terms ~ skos:example
scope etc. notes ~ skos:definition
Conclusions
Some elements of freely faceted cl’s are shared with other KOS types while others are peculiar
Some of the latter (facet categories, place of definition…) are hard to be represented carefully in existing markup languages
Conclusions
FFCs are complex, rich systems requiring special treatment
More representation work is needed, possibly involving SKOS extensions or other markup languages
thanks
www.iskoi.org/ilc