A Practical Guide to Dewey Decimal Classification - Hardcoverby Karen Snow (Author) A Practical Guide to Dewey Decimal Classification is a hands on introduction to the world's most frequently used classification system. The book gives a brief history of the scheme and discusses the theory behind the organization and construction of Dewey class numbers, as well as using WebDewey, the online resource for accessing DDC. Author Biography Karen Snow is associate professor and PhD program director in the Graduate