Linking lcsh and other stuff
6 likes933 views
Owen Stephens discusses the Library of Congress Subject Headings (LCSH) and its representation in linked data during a talk on July 14, 2011. He shares insights from his work with linked data projects at the Open University, particularly the Lucero and CORE projects that involve harvesting metadata and establishing relationships between published papers. The document emphasizes the complexity of LCSH, including its pre-coordinated structure and the importance of authorized headings, while also suggesting improvements in how subject headings are represented within linked data frameworks.
Linking lcsh and other stuff
- 1. Linking Library of Congress Subject Headings Owen Stephens 14th July 2011 @ostephens http://www.meanboyfriend.com/overdue_ideas Thursday, 14 July 2011
- 2. LNKNLCSH @ostephens Thursday, 14 July 2011 This is the lightning version I should precursor this talk by saying I’m really pleased that the LoC have invested in experimenting with Linked Data representations of aspects of their data. Anything in this talk isn’t a criticism of this, but about the issues we encountered using aspects of the data. It’s possible that some or all of these problems may have been down to my lack of understanding of LCSH and Linked Data :)
- 3. Library chops Thursday, 14 July 2011 I’m a librarian - by nature and qualification :) - see http://www.meanboyfriend.com/ overdue_ideas/2010/11/library-routes/ Been working on the cusp between libraries and IT since 1995. Spending early part of my career in small libraries means I have worked in just about every area of library front of house and back office. However although I’ve catalogued books, and have more than a passing familiarly with MARC, I’m not a cataloguer, and not an expert on LCSH
- 4. Linked Data chops Thursday, 14 July 2011 I’ve been trying to understand the Semantic Web/Linked Data for several years :) My understanding has been accelerated over the last couple of years by involvement in several projects in the Linked Data space. Specifically the Lucero and CORE projects at the Open University
- 5. Thursday, 14 July 2011 Expressing similarity between published papers in UK research repositories Harvest metadata and full-text (50k papers from 143 UK repos so far) Text mine for relationships Expose ‘similarity’ measure as RDF triples using MuSIM Ontology (originally developed for Music, but equally applicable) For more information http://core-project.kmi.open.ac.uk
- 6. Exposing RDF Thursday, 14 July 2011 Three ʻproductsʼ CORE Portal - search or SPARQL metadata for harvested papers CORE Mobile – Android application to search & navigate across related papers & downloading articles CORE Plugin - Designed to integrate into existing repository interface to link to ʻrelated papersʼ in other repos, based on CORE ʻsimilarityʼ For more information http://core-project.kmi.open.ac.uk SPARQL Endpoint at http://core.kmi.open.ac.uk:8081/COREWeb/squery How we express data in RDF: http://core-project.kmi.open.ac.uk/node/13
- 7. Lucero Thursday, 14 July 2011 For more information see http://lucero-project.info Data and SPARQL Endpoint available via http://data.open.ac.uk Lucero published variety of data from the Open University as linked open data - admin data (buildings), course data (course catalogue, OERs), research data and data about bibliographic resources - including materials in the library (focussed on materials related to course materials - around 30k catalogue records)
- 8. LCSH Thursday, 14 July 2011 Lots been written about LCSH, it’s structure, whether it should be replaced. I don’t want to spend too much time on this today but it may come up in places However it is probably worth recapping my understanding (if only to let those more knowledgeable correct it) Key aspect in the context of this talk is that LCSH is primarily a pre-coordinated system - that is facets of subject headings are pre-combined into a single, multi-faceted heading. Although.... “LCSH itself requires some degree of post-coordination of the pre-coordinated strings to bring out specific topics of works.” (http://www.loc.gov/catdir/ cpso/pre_vs_post.pdf) In fact the way that LCSH is structured in MARC records, and the way that indexes can be built on this in library management systems means that I’m going to focus on ‘Topical’ subject headings (confusingly to me, LCSH can also cover Name, Title and Geographic headings) Topical Terms can represent “a concrete object, animal, etc.; a category of people, animals, or objects; a more abstract concept, belief, process, or phenomenon; an institution, etc.” (http://www.tulane.edu/~techserv/lcsh%20introd.html) Topical LC Subject Headings are built by combining ‘Topical Terms’ with qualifiers (‘subdivisions’) which allow you to contextualise the term. The types of subdivision available are: General (a high level general qualifier - e.g. ‘History’) Chronological (period of time - e.g. ‘20th Century’) Geographic (place - e.g. ‘Great Britain’) Form (the type/genre of material - e.g. ‘Dictionary’) There are large number of rules that express how these subdivisions can be used in conjunction with Topical Terms, and the order in which they should be expressed. Not all combinations are valid - for example only certain General subdivisions may be further subdivided Geographically. The rules are not always black and white - they have ‘examples’ lists which you can use to inform you if it might be valid in a given situation. Perhaps suffice to say that a document called ‘BASIC SUBJECT CATALOGING USING LCSH: Trainee’s Manual’ is 382 pages long. Subject heading strings can be valid (i.e. constructed according to rules/patterns) while not being ‘Authorized’ - in this context and Authorized Heading is “A preferred subject term as decided and established by the Library of Congress by means of an authority record.” (Thanks to Tom Meehan for this definition)
- 9. Thursday, 14 July 2011 Thanks to work of Ed Summers and others, the Library of Congress have a Linked Data representation of LCSH in SKOS. However, this only covers ‘Authorized’ LCSH - presumably because only those LCSH with an Authority record have an identifier within LoC systems? (I’m speculating)
- 10. Thursday, 14 July 2011 This is a catalogue record from the OU - the two strings listed as ‘Subjects’ are LCSH (for cataloguers amongst you MARC 650s) Can see the linked data representation at http://data.open.ac.uk/page/library/289148
- 11. General Subdivision Science--Study and Teaching--Research Topical General Term Subdivision Thursday, 14 July 2011 This is made up of a Topical Term - Science and two general subdivisions ‘Study and Teaching’ and ‘Research’
- 12. Science--Study and Teaching--Research id.loc.gov ? Thursday, 14 July 2011 This is (afaik - I trust the cataloguers) a valid LCSH ... however it is not authorized ... and so does not have a URI on id.loc.gov
- 13. Science--Study and Teaching--Research http://id.loc.gov/authorities/sh85118587#concept Thursday, 14 July 2011 “Science--Study and Teaching”, however, is an authorized heading
- 14. Science--Study and Teaching--Research http://id.loc.gov/authorities/sh85118553#concept N.B. This is URI for Science as Topical Term not http://id.loc.gov/authorities/sh00007934#concept which is URI for Science as a General Subdivision Thursday, 14 July 2011 As is “Science”
- 15. Science--Study and Teaching--Research http://id.loc.gov/authorities/sh2001008697#concept Thursday, 14 July 2011 Also “Study and Teaching” (as a topical subdivision) is an authorized heading
- 16. Science--Study and Teaching--Research http://id.loc.gov/authorities/sh2002006576#concept N.B. This is URI for Research as General Subdivision not http://id.loc.gov/authorities/ sh85113021#concept which is URI for Research as a Topical Term Thursday, 14 July 2011 Also “Research” (as a topical subdivision) is an authorized heading
- 17. More links please Thursday, 14 July 2011 If we only used id.loc.gov URIs where we had an authorised LCSH, we would end up with only a small number of links. Some URIs in id.loc.gov would never be used in this way as they only represent subdivisions - never valid by themselves. Therefor decided to check a variety of combinations against id.loc.gov
- 18. Science--Study and Teaching--Research Science--Study and teaching http://id.loc.gov/authorities/ sh85118587#concept http://id.loc.gov/authorities/ Science sh85118553#concept http://id.loc.gov/authorities/ Study and Teaching sh2001008697#concept http://id.loc.gov/authorities/ Research sh2002006576#concept Science--Study and Teaching-- http://data.open.ac.uk/page/topic/ library/science-- Research study_and_teaching--research Thursday, 14 July 2011
- 19. MADS? http://www.loc.gov/standards/mads/rdf/ Thursday, 14 July 2011 As far as I can see MADS (apart from looking complex) models the Authority - not the heading - this doesn’t solve the problem we saw here! That is MADS would solve the problem only for Authorized headings (which it does represent as component parts - which I think addresses the issues raised by Karen Coyle at http:// kcoyle.blogspot.com/2009/05/lcsh-as-linked-data-beyond-dash-dash.html) Happy to be corrected...
- 20. A different approach? bibo:authorList ( <http://examples.net/contributors/2> <http://examples.net/contributors/1>) lcsh:headingList ( <http://id.loc.gov/authorities/ sh85118553#concept> <http://id.loc.gov/authorities/ sh2001008697#concept> <http://id.loc.gov/authorities/ sh2002006576#concept>) Thursday, 14 July 2011 If we could use rdfs:list to represent the pre-coordinated string of headings - then wouldn’t care about whether ‘authorized’ or not, and would have all the individual headings there as well (bibo lists authors individual and as a list) Again copying BIBO which has each author as a dc:author as well, could represent each part of the subject string as a separate dc:subject. In a MADS world there would be advantage to expressing full authorized heading as well (for relationships derived in MADS) although there is still the question of expressing ‘authorized fragments’ which seems to me would also be useful with MADS for the same reasons This feels like a simple approach that would at least allow us to capture the component parts of subject string (and personally I’m not sure we ought to go further than this? do we need to? why?). My feeling is lots of the work goes into representing the ‘Authority file’ as opposed to how subject headings are used in the real world ... is this fair?
- 21. Details: http://discovery.ac.uk/developers/ competition/ Datasets: http://ckan.net/group/ ukdiscovery Ask Questions: http://getthedata.org or #discodev Thursday, 14 July 2011 Finally just an advert - if you are interested in open data in the library/archive/museum space please consider entering this competition :) - really show the value of this stuff!