Fun with Google Ngram Viewer, pt. 2.

The chart below delineates references to five library classification schemes (Dewey Decimal Classification, Library of Congress Classification, Universal Decimal Classification, Colon classification, and Bliss Bibliographic Classification) in books published between 1950 and 2008. As the search terms are relatively uncommon in the Google Books corpus, I’ve smoothed the data by using 5-year rolling averages. The terms are case-insensitive.

ngram (major classification schemes)

Classifiers won’t be surprised to see DDC and LCC dominating today. Published interest in other schemes has almost been extinguished in the English-speaking world. But the early data hints at a radically different perspective on library classification two generations ago, when faceted schemes looked like realistic alternatives to the two (mainly) enumerative schemes now ascendant.

In the late 1950s, there were more printed references to UDC than to any other scheme; the same was true of Colon classification in the early to mid 1960s. Interest in BC peaked in the 1980s. No other classification scheme generates statistically meaningful data.

The fall-off in discussion of individual schemes has not been as precipitous as that for library classification generally. Updates to DDC and LCC continue to be published regularly, maintaining a background hum of references.


The Google Ngram Viewer visualizes phrase and word usage across the 5.2 million books digitized by Google up to 2012. Results are normalized by the number of books published in each year, and smoothed using a moving average of three years. The chart for ‘library classification’ shows a worrying trend.

ngram (library classification)

It makes sense that interest in classification, as reflected in Google’s corpus, peaked in the 1960s. Many American research libraries converted to LCC at this time. The decade was also the heyday of Classification Research Group, based in London, and the Classification Research Study Group, led by Phyllis Richmond.

But have yesterday’s questions about classification really been settled? With most public and school libraries using Dewey, and academic and research libraries using LCC, is there nothing more to talk about? Have online tools such as Classification Web, WebDewey, and OCLC’s Classify, replaced the need for classification training in library pedagogy, and left communities of practice with little to discuss?

If so, we’re becoming dangerously complacent. LC does a superb job of maintaining LCC, but as I’ve argued elsewhere, the scheme suffers from systematic bias. Dewey is even worse – it maintains the prejudices of its creator, and the overconfidence of a precocious young man straight out of his undergraduate degree.

Dewey is so hopelessly out of date, and unnecessarily overcomplicated, that viable alternatives are now being implemented. But how can we reclassify if we’ve stopped talking about classification? And how can we classify if we don’t even know what classification is?