Singing from the same hymn sheet

Graham Bell
Opinion - Publishing 08 July 2014

Graham Bell describes Thema, the new subject classification for the global book trade.

Subject classification of books lies at the heart of discoverability, improved merchandising, sales and market intelligence. Describing what books are about - in a consistent and controlled manner - is critical for publishers, booksellers and readers. For readers, subject classification drives physical shelving schemes and online "browse by subject". For booksellers, subject data is used to ensure the right mix of products is available. And for publishers, learning from the successes and failures of previous, similar books is crucial to developing their lists.

The book business has become ever more international, aided in part by the ubiquity of the ISBN, and by international exchange of metadata via frameworks like ONIX for Books. Yet subject classification has remained resolutely bound to national schemes. In the UK, the BIC subject scheme from Book Industry Communication is all but universal, but in North America, the BISAC scheme maintained by the Book Industry Study Group holds sway - and the remainder of the English-language publishing world is forced to use both.

The French book trade uses the Thèmes CLIL scheme, and in Germany the trade uses the Warengruppen-Systematik classification scheme. All this adds cost and complexity to international bookselling, leading Michael Tamblyn of Kobo to coin the term "map-o-rama" for the complex cat's cradle of translations or mappings between schemes.

The potential value of a single, global classification scheme is clear: it lies in reduced duplication of work where more than one scheme is in use, in the elimination of costly and imprecise mapping processes, and in avoiding the loss of precision that's inevitable in such mappings. A global scheme also enables international market research, comparisons and benchmarking, and this value grows with the increasingly international nature of the book trade.

Bridging the fault lines
Yet until very recently, these national schemes, fault lines in the metadata landscape, were seen as unavoidable - just a part of the geography. Thema is a new subject classification scheme that's intended to bridge these faults. Development involved book trade representatives from nearly 20 countries. As a result, it's been designed from the outset for international use, and it has already gathered widespread international support including an endorsement from the International Publishers Association.

The origin of Thema lies in an attempt to "internationalise BIC". The UK's BIC subject category scheme is clearly and deliberately "British" in flavour, attuned to the needs of the UK book trade. During 2011 and early 2012, a proposal for a more internationally balanced version of the BIC scheme named IBIC emerged. This built on the experience of modified versions of the BIC scheme that were already in use in Italy, Spain and other countries. IBIC itself was never properly released, though an early version of it is in use in Spain. But the IBIC project led to the formation of a much larger group of stakeholders willing to work on a global scheme that ultimately became Thema. Critically, this larger group included the developers of the BISAC subject scheme.

Thema aims to be global in scope, multicultural and multi-lingual. It's applicable to all parts of the book supply chain, and is flexible enough to allow each market to retain its unique cultural voice, while remaining a unified and simple-to-adopt standard. Initially, it can be used alongside the existing national schemes, and has the potential eventually to replace them - though this is not an immediate goal.

The Thema project was launched in October 2012, gathering immediate support from trade organisations in more than a dozen countries. Frankfurt 2013 saw the formal launch of version 1.0 of Thema, plus the first meeting of the Thema International Steering Committee, the body that will oversee its future evolution. Some software vendors are now building Thema into their publishing management applications.

Subject hierarchy
Since Thema grew from IBIC, it looks and works a lot like the original BIC scheme. But close up, there are some very significant differences: Thema has incorporated ideas and experience from a number of other established national subject schemes. It lays out a hierarchy of subjects: 20 top level categories, each subdivided into many sub-categories, and each having a heading (eg Geological surface processes (geomorphology)), an alpha-numeric code (eg RBGD) and, in some cases, associated notes. There are around 2,500 subject headings in total. In addition, there are post-coordinated "qualifiers" that can be used to refine the meaning of the main categories with geographical, historical or stylistic nuances. For anyone used to BIC, this is seemingly familiar stuff, but there are significant differences of emphasis, and uniquely, Thema has a mechanism to add country-specific details to the qualifiers too.

Although most of the Thema headings are defined originally in English, the intention is to translate the scheme into multiple languages - so the subject code MKE is labelled dentistry, Zahnheilkunde, odontología and ARABIC and so on. The codes are language-independent, so metadata that includes Thema categorisations is highly portable. In the few months since launch, a full German translation has been completed, and French, Italian and others are under way.

Free of charge
Thema is managed by EDItEUR, the international trade standards body for the book trade. This puts it under the same roof as ONIX, EDItX and other metadata, identifier and e-commerce standards. And like those other EDItEUR standards, Thema is free of charge for anyone to use. Although EDItEUR's work on Thema and its other standards is funded through membership fees (and new members are always very welcome), there is no requirement for membership. This is possible because BIC and Nielsen have kindly donated the relevant intellectual property (derived from the original BIC scheme) to EDItEUR.

Publishers who are concerned with the difficulties of using multiple national subject classification schemes, or with the cost of maintenance and imprecision of mappings from scheme to scheme, should consider implementing Thema alongside their own national or internal subject schemes, and should embed the Thema codes in the metadata they distribute to their supply chain partners. The global nature of Thema makes this particularly important for publishers who expect growth in the ebook market or who trade with international ebook retail platforms, or those who export a significant proportion of their physical products.

Retailers selling books or ebooks that are traded internationally should also consider making use of Thema as a source of subject information, to drive "browse by subject" and search functionality on websites and in internal systems, and to guide physical merchandising plans. There are various Thema resources available from the EDItEUR website to get you started.

Thema brings huge value to the global book trade, and if the first six months since its release is a guide, it has a bright future.

Graham Bell is Executive Director of EDItEUR.

This article first appeared in the Publishers Weekly/BookBrunch London Show Daily.

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