What’s Dewey all about?

Dewey at Cardiff
The Dewey Decimal Classification (DDC) system is one of the main classification schemes used at Cardiff University.  Primarily used in the science based libraries you will see it for instance being used in the Health Library and the Biomedical Sciences library, it is also used in the Architecture and Aberconway libraries and perhaps slightly more surprisingly in Life Long Learning (Senghenydd).

Some history…
DEWEYThe system was originally created by an American librarian, Melvil Dewey (1851-1931) in 1876 when he was hired to classify the library at Amherst College.  He based his system on a ten class structure of knowledge – a sort of attempt to classify the world and all human knowledge as it was known in the 19th century.  Dewey was director of the New York State Library between 1888-1906, founded the Lake Placid Club in 1895, and was apparently a bit of a womaniser!

How does it work? (the basics)
The Dewey Decimal Classifaction system has ten classes, each with ten divisions, which each have ten sections.  We wont give you a full break down of these classes, but they include 300 (Social science), 500 (Science), 600 (Technology – which includes medicine), and 900 (History & geography).  So, if we take the number 616 we see that it comes from the 600 class (technology), then the 610 division (medicine), then the section 616 for disease.

After the 3 digit number we have a decimal point, and then further subdivisions.  Some of these come from the standard subdivisions contained in the tables in volume 1 of DDC, such as geographical locations = .9 (indicates history & geography), 429 (the number for Wales), so 610.9429 = Medicine in Wales.

Within the schedules the subdivisions for all the classes are given, for e.g.  616.39042 (Nutrition & metabolic diseases – inborn errors of metabolism), or 659.1342 (Outdoor advertising).  Occasionally these numbers have the potential for getting quite long, if you want to get really specific, for instance 362.19892000942393 (Paediatric care in Bristol).  However, as you can tell, when the numbers start getting really long they do get a bit confusing for people in the library – both for library staff shelving the books, and library users trying to find something they want (and it gets harder to fit the numbers on the spine labels!).  But remember, its not a case of cataloguers trying to be annoying – we are just trying to make the numbers specific; however don’t worry, you won’t see too many spine labels with 14 digits after the decimal point – we try not to be that cruel!

Until a few years ago the libraries in the Cathays Campus only used a majority of 5 numbers after the decimal point, but this meant that numbers were being cut short at inappropriate moments.  For instance many books on town planning at 711.4 all ended 0942 – which means England and Wales.  This meant that a lot of books had the same number, and made it harder to find specific items on the shelf.  By getting rid of this artificial cut off point, a book on town planning can now have a number specific to the actual town it is about, eg 711.40942987 (Cardiff).  Ideally this means that all books on town planning on Cardiff can be shelved together, instead of being lost amongst books about Birmingham, Manchester, London, Bristol, etc etc.

We don’t expect you to know all the numbers in DDC – even the cataloguers don’t know them all!  However, you may find as you gain familiarity with the books on your subject that you start recognising numbers; by also realising that the subdivisions often come from tables, and are standardised, you may find yourself noticing patterns, such as 09429 at the end of a number meaning Wales, or 076 indicating it is an exam question book.

Some facts and figures!
Blackbox 022We are currently on the 23rd edition, published in 2011, in a 4 volume format; DDC is also available in an online version that is updated monthly.
200,000 libraries in 138 countries use DDC, and it is translated into over 30 languages.
The ninth editor of DDC retired in Jan 2013, so they are now onto their 10th since 1876.

If you’ve enjoyed this whirlwird tour of Dewey, check out 025.431 The Dewey blog for futher information.