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28 DigiCULT
A C
ASE
S
TUDY
OF
A
F
ACETED
A
PPROACH
TO
K
NOWLEDGE
O
RGANISATION
AND
R
ETRIEVAL
IN
THE
C
ULTURAL






H
ERITAGE
S
ECTOR
By Douglas Tudhope and Ceri Binding
I
NTRODUCTION
: K
NOWLEDGE
O
RGANISATION
S
YSTEMS
IN
D
IGITAL
H
ERITAGE
T
he trend within museums and digital heritage
institutions to unlock the information in their
collections involves opening up databases, previous-
ly the domain of the IT department, to a new range
of users. These might, for instance, be members of
the public searching a museum Website for informa-
tion relating to an object which has been in the fam-
ily for generations or they might be curators looking
to create a virtual exhibit
1
from the objects in the
collections database. There is a need for tools to help
formulate and refine searches and navigate through
the information space of concepts that have been
used to index the collection. When technical terms
are involved, a `controlled vocabulary' is generally
used to index the collection ­ if both searchers and
indexers draw on the same standard set of words then
the synonym mismatch problems common with Web
search engines can be avoided. Controlled vocabular-
ies provide a means to standardise the terms used to
describe objects, by limiting the indexing vocabulary
to a subset of natural language.
These controlled vocabularies have long been part
of standard cataloguing practice in libraries and muse-
ums and are now being applied to electronic reposi-
tories via thematic keywords in resource descriptors.
Metadata sets for the Web, such as Dublin Core, typi-
cally include the more complex notion of the Subject
of a resource in addition to elements for Title, Cre-
ator, Date, etc. However, controlled vocabularies can
do more than simply supply a list of authorised terms.
They play a significant role, particularly when used to
provide a mediating interface between indexed col-
lections and users who may be unfamiliar with native
terminology. This applies to both existing collection
databases and new collections of records, which may
be `born digital' but can be categorised and indexed
using the same structures and techniques.
Knowledge is structured and organised so that a
user can explore a network of related concepts to
find the most appropriate one for a given situation.
The different types of Knowledge Organisation Sys-
tem (KOS) include classifications, gazetteers, lexi-
cal databases, ontologies, taxonomies and thesauri.
2
There is a vast existing legacy of these intellectual
knowledge structures (and indexed collections) to be
found within cultural heritage institutions. A library
might use the Dewey Decimal Classification (DDC),
for example, while a museum might use the Art and
Architecture Thesaurus (AAT). Other large, widely
used KOS include AGROVOC,
3
CABI,
4
Library of
Congress Subject Headings, MeSH,
5
and many oth-
ers.
6
On the other hand, a large number of small-
er KOS have also been designed to meet the needs
of specialist applications or subject areas. In the UK,
the mda (Museum Documentation Association)
7
has
facilitated the development of several specialised the-
sauri, such as the Archaeological Objects Thesau-
rus, the Railways Object Names Thesaurus and the
Waterways Object Names Thesaurus.
N
ETWORKING
KOS
SERVICES
T
he rich legacy of KOS makes it possible to
offer search options that go beyond the cur-
rent generation of Web search engines' minimal
assumptions on user behaviour. However, this will
require new thinking on the services that KOS can
offer to the digital environment. Traditionally, atten-
tion has focused on methods for constructing KOS,
with a view to their being used as reference mate-
rial in print form. New possibilities have emerged
1
e.g. the Science
Museum's Exhiblets: http://
www.sciencemuseum.org.
uk/collections/exhiblets/
index.asp
2
Gail Hodge gives a useful
summary: http://nkos.slis.
kent.edu/KOS_
taxonomy .htm
3
Food and Agriculture
Organization of the United
Nations: AGROVOC
Multilingual Thesaurus
(Arabic, Chinese, English,
Français, Español,
Português), http://www.
fao.org/agrovoc/
4
CAB International: CAB
Thesaurus, a controlled
vocabulary resource
[over 48,000 descriptive
terms] for the applied life
sciences, http://www.
cabi-publishing.org/
DatabaseSearchTools.
asp?PID=277
5
National Library of
Medicine: Medical Subject
Headings (MeSH), http://
www.nlm.nih.gov/mesh/
6
For indexes of KOS on
the Web, see http://www.
lub.lu.se/metadata/subject-
help.html and http://www.
w3.org/2001/sw/
Europe/reports/thes/
thes_links.html
7
mda (Museum
Documentation
Association), http://www.
mda.org.uk/index_rs.htm