Tag Archives: ontologies

ISKO UK 2013 – provisional programme

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Estimated reading time 2–2 minutes

I will probably be on the other side of the Atlantic when the ISKO UK conference takes place in July in London, UK. I will be sorry to miss it, because the committee have brought together a diverse, topical, and fascinating collection of speakers.

ISKO UK excels in unifying academic and practitioner communities, and the conference promises to investigate the barriers that separate research from practice and to seek out boundary objects that can bring the communities together.

This is demonstrated in person by the keynote speakers Patrick Lambe of Straits Knowledge and Martin White of Intranet Focus Ltd – both respected for their commercial as well as academic contributions to the field of Knowledge Organization.

Amidst what is already shaping up to be a very full and varied programme, the presentations by Jeremy Tarling and Matt Shearer (BBC News) and Jarred McGinnis and Helen Lippell (Press Association) will show how research in semantic techniques is now being put to practical use in managing the fast-flowing oceans of information that news organizations handle.

The programme also includes a whole session on combining ontologies with other tools, as well as papers on facet analysis and construction of controlled vocabularies. There’s even some epistemology to please pure theoreticians.

Building, visualising and deploying taxonomies and ontologies; the reality – Content Intelligence Forum event

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Estimated reading time 1–2 minutes

I have been trying to get to the Content Intelligence Forum meetups for some time as they always seem to offer excellent speakers on key topics that don’t tend to get the attention they deserve, so I was delighted to be able to attend Stephen D’Arcy’s talk a little while ago on taxonomies and ontologies.

Stephen has many years of experience designing semantic information systems for large organisations, ranging from health care providers, to banks, to media companies. His career illustrates the transferability and wide demand for information skills.

His 8-point checklist for a taxonomy project was extremely helpful – Define, Audit, Tools, Plan, Build, Deploy, Governance, Documentation – as were his tips for managing stakeholders, IT departments in particular. He warned against the pitfalls of not including taxonomy management early enough in search systems design, and the problems that you can be left with if you do not have a flexible and dynamic way of managing your taxonomy and ontology structures. He also included a lot of examples that illustrated the fun aspects of ontologies when used to create interesting pathways through entertainment content in particular.

The conversation after the talk was very engaging and I enjoyed finding out about common problems that information professionals face, including how best to define terms, how to encourage clear thinking, and how to communicate good research techniques.

Transforming and extending classification systems – UDCC Seminar

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This post is the last in a series about the UDC consortium international seminar in The Hague, 19-20 September, 2011

Joan S. Mitchell, OCLC (USA), and Marcia Lei Zeng, Kent State University (USA), supported by Maja Žumer, University of Ljubljana (Slovenia), talked about extending models for controlled vocabularies to classification systems: modelling DDC with FRSAD, which led to interesting discussions about their concepts of “nomen” and “thema”.

Along with my former colleague Andy Heather, now CTO at DODS Parliamentary Communications Ltd, I talked about our work on the data migration of classifications from a legacy database into new taxonomy management software, presenting our paper: Transformation of a legacy UDC-based classification system: exploiting and remodelling semantic relationships.


The key ideas I took away from the conference were:
1) Classifications and ontologies are not an either/or choice. They have different properties and different strengths and weaknesses and so should be chosen according to the task in hand.
2) It is difficult to turn a classification into an ontology, but easy to turn an ontology into a taxonomy, so if you don’t have either to start with and can’t decide, an ontology is a safer bet. If you already have a classification, you need to think carefully about whether it is worth turning it into a fully modelled ontology, as converting it to RDF or SKOS is likely to be much easier. However, at the moment, RDF and SKOS have limitations, especially in handling faceted taxonomies, so beware of losing semantic richness in the conversion process. Polyhierarchies offer a way of expressing facets in SKOS.
4) Vocabulary control and alignment continue to be significant issues for the Semantic Web.
5) Ontology curation, management, and semantic alignment will be increasingly important issues for the Semantic Web.

Slides and audio recordings of all 21 talks can be now downloaded from the conference website.

Conference proceedings are published by Ergon Verlag and can now be
purchased/ordered online from http://seminar.udcc.org/2011/php/proceedings.php.

Classification and ontology in specific subjects – UDCC Seminar

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Estimated reading time 3–5 minutes

Day two of the UDC consortium international seminar opened with two subject-specific talks – Wolfram Sperber described a classification of mathematics and Andrew Buxton showed how similar chemistry classification and ontologies are, using the ChEBI ontology. He also described the different ways classifications and ontologies could be used to support each other and about the lack of good graphical tools and visualisations to represent ontologies.

Categories and relations: key elements of ontologies – Categorial Distinctions

Roberto Poli, University of Trento (Italy) talked about the compliexisties of part-whole relationships. There are simple wholes, composed of a sum of their parts, but some parts of wholes cannot simply be added together – for example, the social, psychological, and physical aspects of a person. He also discussed the difference between science as epistemological – dealing with what can be known – and ontological – deraling with what exists.

Towards a relation ontology for the Semantic Web

Dagobert Soergel made a bold claim that the only way for the Semantic Web to deliver its promise is if we adopt a relation ontology and map each dataset to the standard, to allow interoperability. He pointed out that you “do not getting semantics from syntax alone”.

Relations in the notational hierarchy of the Dewey Decimal Classification

Rebecca Green from OCLC described the difficulties encountered when trying to automatically create ontologies from the Dewey Decimal Classification. These included semantic differences in the way subclasses had been defined, meaning that no single rule would handle them all appropriately.

Modelling concepts and structures in analytico-synthetic classifications

The eminent Ingetraut Dahlberg compared Aristotle and Ranganathan’s key facets and UDC and Colon Classification systems. She also presented a survey of academic subject areas analysed into facets.

Representing the structural elements of a freely faceted classification

Claudio Gnoli of the University of Pavia, talked about freely faceted classifications, in comparison with systems such as UDC. He emphasised the urgency of publishing classifications on line, but highlighted the limitations of SKOS and OWL to fully expressed faceted systems despite the fact that faceted systems are extremely good tools for obtaining precise search results. Faceted systems are also excellent for combining information across disciplines, allowing you to combine aspects of one subject areas with aspects of a different one, and interdisciplinarity is becoming increasingly important as an approach, as innovation often happens at the boundaries between disciplines.

He pointed out that a polyhierarchical approach can be modelled in SKOS as a way of representing facets, but that this approach is often overlooked. He also called for more work to be done on SKOS so that it can represent facets directly.

Facet analysis as a tool for modelling subject domains and terminologies

Vanda Broughton, University College London, offered the Bliss Classification as a useful tool for online subject classification, but called for help in how best to publish it for general use. Should it be released as a text document, database, or should work be done to convert it to an ontology – and if so, in what form?

She stressed how the logical approach of facet analysis and regular syntax makes it predictable and hence ideal for machine manipulation.

Analytico-synthetic approach for handling knowledge diversity in media content analysis

Devika P. Madalli, Indian Statistical Institute, DRTC (India), described the Living Knowledge project that used an analytico-synthetic approach in order to bring together around useful themes diverse content from different sources using varied means of expression. This supported a rich faceted search system.

Slides and audio recordings of all 21 talks can be now downloaded from the conference website.

Conference proceedings are published by Ergon Verlag and can now be
purchased/ordered online from http://seminar.udcc.org/2011/php/proceedings.php.

Classification meets the Web – UDCC Seminar 2011

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Estimated reading time 2–2 minutes

This post is 4th in a series about the UDC consortium international seminar in The Hague, 19-20 September, 2011.

Interoperability of knowledge organization systems with and through ontologies

Daniel Kless from the University of Melbourne pointed out that problems with ontologies arise when combining them, as errors in combination can have disastrous effects on subsequent reasoning. A well-defined modelling method is needed to minimise this. Standards such as OWL and RDF do not address the problems of methodology or terminology control.

Towards the integration of knowledge organization systems with the linked data cloud

Vincenzo Maltese of the University of Trento, Italy, explained how it is vital to make clear the semantics and purpose of any ontology when attempting to share Linked Data. Ontologies may differ in their scope, purpose, structure, terminology, language, coverage, formality, and conceptualization. He drew a distinction between descriptive ontologies and classification ontologies. It is very easy to convert a descriptive ontology to a classification ontology and the process can be automated, but extremely difficult to convert a classification ontology to a descriptive one and the process requires human intellectual and editorial effort.

Classification and reference vocabulary in linked environment data

Joachim Fock of the Federal Environment Agency (Germany) talked about how they transformed their keyword thesaurus to a Linked Data format.

Classifications and ontologies on their own terms – UDCC Seminar 2011

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Estimated reading time 2–2 minutes

This post is the third in a series about the UDC consortium international seminar in The Hague, 19-20 September, 2011.

Approaches to providing context in knowledge representation structures

Barbara Kwasnik, Syracuse University (USA), talked about ways that context can be used as a disambiguation tool, and described different kinds of contexts: warrant, scientific, educational, cultural, etc. However, interdisciplinary approaches can be difficult. It is easy to have different ontological commitments, but you need a mapping to know when and which bits need to work across domains. Ontologies will need updating as the world and world views shift and change, so we need ways of defining their scope, as well as provenance and mappings. There are also difficulties in establishing the neutrality of ontologies.

Interaction between elementary structures in universes of knowledge

Richard P. Smiraglia, University of Wisconsin (USA),
talked about how people want to turn the multidimensional world into a unidimensional top-down model. He pointed out that people tend to assume UDC is like Dewey, but it actually works far more like Ranganathan’s Colon Classification. He called for new theories of organizing knowledge in shifting contexts and theories about how to mediate between concepts and structures like UDC.

Demystifying ontology

Emad Khazraee, Drexel University (USA), talked about how ontological approaches are as old as literature itself, showing a picture of what I think was the ancient Sumerian king list. He talked about boundary objects and the overlap between different academic areas that are interested in knowledge organisation and learning. He also discussed the differences between ontology-as-categorial-analysis and ontology-as-technology.

The role of classification and ontology on the Web – UDCC Seminar 2011

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Estimated reading time 2–3 minutes

This post is the second in a series about the UDC consortium international seminar in The Hague, 19-20 September, 2011.

Knowledge Organization Systems (KOSs) as hubs in the Web of Data

In a minor change of schedule, Thomas Baker from the DCMI talked about some of the practical issues with using Linked Data. Provenance data can be recorded as additional information but it is not standardised or an integral part of RDF and this is something that is a growing concern, receving attention from W3C. URI persistence and alignment remain concerns for data managment and governance.

Aligning web vocabularies

Guus Schreiber also dealt with the problem of making sure we are all talking about the same thing when we try to align our vocabularies. He called for ontologists to be modest about what they can achieve and not to try to hide the problems that occur when you try to transfer an ontology form one domain to another. Errors typically occur due to failures to notice subtle differences between domains.

Vocabulary alignment is a complex business that requires a lot of intellectual effort and multiple techniques should be used to reinforce and support each other. It is much better to map small vocabularies to large ones that can then act as “pivots”.

There is still no adequate methodology for evaluating alignments nor for mediating consensus between observers. Perhaps there should be a way of recording the strength of consensus and the presence of disagreements and alternative views.

Classification, Collaboration and the Web of Data

Dan Brickley described three types of graph – the hypertext graph of the Internet’s links between documents, the social graph of links between people, and the factual graph of links between data. Currently Linked Data is bringing together the hypertext and factual graphs, and another step would be to add in the social dimension.

He called for a focus on what the various tools can actually do, to be wary of over-evangelical ontologists, and to remember that subject classifications are strong and robust tools that are more appropriate for many types of work than ontologies.

He said that you could expect Linked Data to solve about a third of your information linking problems.