Facet analysis and its influence on the major systems of library classification
Submitting InstitutionUniversity College London
Unit of AssessmentCommunication, Cultural and Media Studies, Library and Information Management
Summary Impact TypeCultural
Research Subject Area(s)
Information and Computing Sciences: Artificial Intelligence and Image Processing, Information Systems
Education: Specialist Studies In Education
Summary of the impact
Research on the theory and design of faceted classifications as
exemplified in the Bliss Bibliographic Classification 2nd edition (BC2)
has influenced the recent development of two out of the three
internationally important library classification schemes, the Universal
Decimal Classification, and the Dewey Decimal Classification. Collectively
these are used in over 350,000 libraries worldwide, and thousands of new
publications in the relevant subject classes are now classified using
systems based on research undertaken in UCL Information Studies.
Facet analysis is a powerful methodology for building knowledge
organisation systems such as classification schemes, thesauri, taxonomies
and ontologies [d, e]. It was originally devised by a UCL graduate, S. R.
Ranganathan, in the 1930s, and taken up in the 1950s by the UK
Classification Research Group (CRG), who greatly refined and elaborated
the methodology, and developed a body of theoretical research which forms
a significant part of the overall corpus of research literature in the
fields of indexing and information retrieval. UCL research in this field
is now led by Professor Vanda Broughton (UCL Information Studies, or DIS,
since 1997 and a member of CRG from the early 1970s).
Facet analysis builds classification from `the bottom up' on the basis of
a detailed examination of the concepts in a given discipline or subject
field [b]. Concepts are assigned to a series of categories (or facets)
which are largely functional, or linguistic in nature (entities, parts,
materials, processes, operations, products, agents). Relationships between
concepts in a facet, and between the facets themselves, are established,
and the rules for combination (the system syntax) are derived from the
structure, within the conventions and needs of the particular discipline.
Although there is an established body of theory, different disciplines
present particular difficulties in the work of intellectual analysis.
Research in DIS also involves the investigation of potential new
fundamental categories, and the encoding of data to represent the
structural properties of concepts and their interrelationships. This has
applications not only in libraries, but in machine management, and today
there are many examples of faceted applications in e-commerce, online
searching, etc. Much DIS research has focused on the management and
representation of faceted systems in digital formats which support such
DIS is the institutional base for development of the second edition of
the Bliss Bibliographic Classification (BC2). The original Bibliographic
Classification (BC1) was a well-regarded classification system widely used
in UK academic and research libraries until the 1990s, when, for financial
reasons, it was largely replaced by the Dewey Decimal and Library of
Congress Classifications. The development of BC2, which started in 1977,
resulted in a series of highly structured classifications for different
disciplines, which provide a model of a faceted system built on
theoretical principles. DIS researchers have developed new terminologies
for specific subject fields including religion, the fine arts and
The AHRC-funded FATKS project (2002-2003, PI V. Broughton) in DIS
examined the viability of applying a faceted approach to humanities
vocabulary, and developed an indexing and search tool for two humanities
disciplines, religion and the arts; outputs included the creation of a
relational database, and software for the automatic building of classmarks
[f]. The project documentation and the demonstrator are published on the
FATKS website, http://www.ucl.ac.uk/fatks/about.htm.
DIS researchers working on faceted classification included Professor Ia
McIlwaine (Head of DIS 1993-2001, Editor-in-Chief of the Universal Decimal
Classification (UDC) from 1993-2007), who was responsible for the
implementation of a faceted structure into UDC; Dr Aida Slavic (research
associate on the FATKS project 2002-2003, former DIS doctoral student, and
Editor-in-Chief of UDC from 2011) developed the relational database and
search interface for the faceted humanities vocabulary.
References to the research
[a] Broughton, V. and Mills, J. and Coates, EJ. (2012) Bliss
Bibliographic Classification 2nd edition. Class C Chemistry.
deGruyterSaur: Munich. Submitted to REF2.
[b] Broughton, V. (2011) `Facet analysis as a tool for modelling subject
domains and terminologies'. In Slavic, A. & Civallero E. (eds.) Classification
and ontology: formal approaches and access to knowledge: proceedings of
the International UDC Seminar, 19-20 September 2011, The Hague, The
Netherlands. Würzburg: Ergon Verlag. pp 207-228. Submitted to REF2.
[c] Broughton, V. (2010) `Finding Bliss on the web: some problems of
representing faceted terminologies in digital environments'. In: Gnoli, C.
and Mazzocchi, F., (eds.) Paradigms and conceptual systems in
knowledge organization: Proceedings of the Eleventh International ISKO
Conference. Ergon: Wurtzburg. Available on request.
[d] Broughton, V. (2010) `Concepts and terms in the faceted
classification: the case of UDC'. Knowledge organization, 37, 4
pp. 270-279. Submitted to REF2.
[e] Broughton, V. (2008) `A faceted classification as the basis of a
faceted terminology' Axiomathes 18 (2) pp. 193-210. Springer
online DOI 10.1007/s10516-007-9027-7.
Submitted to REF2.
[f] Broughton, V. and Slavic, A. (2007) `Building a faceted
classification for the humanities: principles and procedures' Journal
of Documentation 63 (5) pp. 727-754.
Output [f] emerged from an AHRC research grant:
`Towards a Knowledge Structure for High Performance Subject Access and
Retrieval within Managed Digital Collections'. PI: Vanda Broughton.
Amount: £46,226 Duration: April 2002-June 2003. AHRC B/IA/AN8003/APN13797.
Details of the impact
Classification research in DIS has had significant impacts on the design
of new versions of two major library classification systems, the Universal
Decimal Classification (UDC) and Dewey Decimal System (DDC), cumulatively
used by over 350,000 libraries around the world. Most existing
classification systems originate before the computer age, employ pragmatic
ideas of knowledge organisation, and lack a sound theoretical basis. Facet
analysis on the BC2 model offers solutions to some of these issues and
enables more accurate representation of subject content, especially
important for online searching and discovery. Of particular importance is
the research into classification in the humanities, and the special
challenges of culture-specific concepts and terminology which they
present; effective ways of managing these difficulties allow for the
elimination of cultural bias which is evident in many older systems, and
the creation of schemes which are more acceptable to minority users.
Impact on the design of UDC library classification
The UDC is an international classification, available in 40 languages,
and used in more than 150,000 bibliographic databases, documentation
centres and libraries in around 130 countries, notably in central and
eastern Europe, where it is the dominant scheme . UDC has to exhibit a
consistent and logical structure — such as that offered by facet analysis
— because of its use in scientific and technical research establishments,
as well as general academic collections, and its application to
documentation as well as books. Collections include VINITI — All-Russian
Scientific and Technical Information Institute of Russian Academy of
Sciences (28 million records), NEBIS — The Network of Libraries and
Information Centres in Switzerland (3m), Romanian Science and Technology
Portal (3m), the national libraries and bibliographies of Slovakia (4m),
Slovenia (3.5m), Hungary, Czech Republic, Croatia, Poland, Finland,
Serbia, Spain and Portugal . Facet analysis also provides for a data
structure that is compatible with the maintenance of the classification in
a database format, and for its machine management. As Ines Cordeiro (UDC
Editor-in-Chief 2007-2011, Deputy Director of the National Library of
Portugal and former doctoral student in DIS) reported in 2007, BC2
provided a model for UDC to achieve its organisational goal of developing
a classification suitable for online environments, not just one designed
for better shelf arrangement .
In the 1990s UDC agreed to make BC2 the basis of all new revisions of the
UDC, using its terminologies and adopting its faceted structure within the
UDC format. In 1997, DIS researcher Broughton joined the Editorial Team to
help achieve this goal, presenting the principles of facet analysis to
editorial workshops, helping to establish editorial policy and practice,
and working on the conversion of BC2 classes to UDC format. Her
identification of the Genesis Problem [d] demonstrates the difficulty of
representing, in a relational database, subject content and terminology
that is specific to particular cultures and traditions. She also developed
several new auxiliary schedules, which assign common facets across classes
In 2000, Broughton created an entirely new Religion classification, based
on her work on BC2 . This was incorporated into the 2005 edition of UDC
and applied to all accessions in religion since. Between 2008 and 2013,
books in 130 countries were classified using this system.
Broughton`s work on Religion  provided precedent for editors
developing other UDC classes. In 2009, a working group led by Claudio
Gnoli began updating Philosophy, explicitly `trying to follow the pattern
of facet presentation introduced in the Class 2 Religion by Vanda
Broughton' , and using her expertise in humanities classification [f].
Revision of the important Class 61 Medicine was announced in 1995. In
2009, its editors, including Ia McIlwaine, outlined the process of
adapting BC2  and how auxiliary schedules created by Broughton were a
major factor in rationalising its structure: `In phase 1, a framework for
the new class was established ... Bliss terminology was used in the
captions together with UDC notation and formatting as needed. Concepts and
terms, the common auxiliaries, and classes related to medicine were used
insofar as they were appropriate. There was heavy use of common auxiliary
tables of general characteristics (Table 1k) -02 Properties, -04 Relations
and Processes, and -05 Persons' .
In 2011, Broughton was invited to explain the BC2 structure of physical
sciences at the UDC Editorial Workshop, and the following year BC2
principles were also considered in the revision of the mathematics class,
with work beginning in 2013 .
Impact on the design of the Dewey library classification system
The Dewey Decimal Classification (DDC) has been translated into more than
30 languages and serves library users in over 200,000 libraries in 135
countries, making it the world`s most widely used library classification
Dewey was consistently criticised for its Class 200, Religion, in which
Christianity and the Bible occupied numbers 220-289, with all other
religions sharing 290-299. A 2005 user survey confirmed this general
discontent with the Religion Class, and with its far greater weighting of
Christianity compared with other religions . In 2006, following the
publication of the new UDC Class 2 Religion, the then-Editor of the DDC
Joan Mitchell proposed collaboration with McIlwaine for a revision
incorporating many features of Broughton`s UDC schedule into the 22nd
edition of Dewey .
When released in 2011, the top structure of the new DDC class mirrored
almost exactly the UDC structure as designed by Broughton. A separate
publication, `developed for libraries with extensive religion collections'
appeared in 2012 . This featured `an optional arrangement for the
Bible and specific religions based on a chronological/regional view, in
order to help reduce Christian bias in the standard notational sequence
for the Bible and specific religions, based on a similar development
introduced in the UDC in 2000' . Between its release in 2012 and 31
July 2013, 178,000 books in the field of religion were added to the
WorldCat database maintained by the Online Computer Library Centre (OCLC),
which also publishes and maintains Dewey; the majority will have received
a new DDC number using this system .
Between them UDC and DDC are used as organising and retrieval tools for
collections in 350,000 libraries across the world. Facet analysis, the
focus of DIS research, has been instrumental in addressing such issues as
logical structure, currency, cultural neutrality, and machine
compatibility in both of these, two of the three leading systems of
library classification. The influence of faceted classification in general
and BC2 in particular has ensured that its advantages are available to
millions of library users.
Sources to corroborate the impact
 Universal Decimal Classification (UDC), (http://www.udcc.org/index.php/site/page?view=about)
and list of collections (http://www.udcc.org/index.php/site/page?view=collections)
 Broughton, V. (2002) `A new common auxiliary table for relations,
processes and operations', Extensions and corrections to the UDC 24
pp. 29-35. Available on request.
 Broughton, V. (2000) `A new classification for the literature of
religion', International cataloguing and bibliographic control
2000 (4) and Paper read at the 66th IFLA Council and General Conference,
Jerusalem, Israel 13-18 August 2000. Available on request.
 Slavic, A., Cordeiro, M., & Riesthuis, G. (2008) `Maintenance of
the Universal Decimal Classification: overview of the past and
preparations for the future', International Cataloguing and
Bibliographic Control 37 (2) pp. 23-29. Available on request.
 Gnoli, C. (2009) UDC Philosophy revision Report 1. UDC
Italia, 7 August 2009.
 Davies, S. (2011). `UDC Editorial Workshop, The Hague, 21 September
2011: a report' Extensions and corrections to the UDC 33 pp.11-12.
 Williamson, N., McIlwaine, I. C. (2009). `UDC Medical Sciences
project: progress and problems'. Extensions and Corrections to the UDC
31 pp. 33-36.
 Statement provided by Editor-in-Chief, UDC, in a personal
communication dated 3 May 2013, available on request.
 Dewey`s Options in Religion: Survey Results (http://www.oclc.org/nl-NL/dewey/discussion/optionsinreligion.html)
 McIlwaine, I., and Mitchell, J. S. (2006). `The New Ecumenism:
Exploration of a DDC/UDC View of Religion'. In Knowledge Organization
for a Global Learning Society: Proceedings of the 9th International ISKO
Conference, 4-7 July 2006, Vienna, Austria, Gerhard Budin, Christian
Swertz, and Konstantin Mitgutsch (eds.), pp. 323-330. Würzberg: Ergon.
Available on request.
 Dewey Decimal Classification web pages (http://www.oclc.org/dewey/versions/religion.en.html)
Announcement of the 2012 release (http://ddc.typepad.com/025431/2012/05/200-religion-class.html)
 Data derived from a search of WorldCat (http://www.worldcat.org/)