Two Unique Systems
If you ask a librarian whether he or she prefers the Dewey Decimal System or Library of Congress Classification, be ready for a geeked out discussion on the merits of hierarchical vs. faceted classification schemes and whether capping the number of categorization classes holds peril or potential. . . . If you're a newcomer to library science, a little background on the classification systems might be helpful.
The Dewey Decimal System was developed in 1876 as a means to organize all knowledge - an ambitious endeavor, to say the least. In this sense, the Dewey Decimal System was the Google of the 19th century, minus the fancy technical aspects. Instead, the cataloging system relies on a simple framework that starts with ten subject classes (religion, social sciences, etc.). These classes are broken down into ten divisions, which are then broken down into ten subdivisions. Books and other resources are assigned numeric call numbers based on where content within them falls in this taxonomy of knowledge.
The Library of Congress Classification system differs in its design. Developed at the turn of the 20th century, it was specifically created to categorize books and other items held in the Library of Congress. It features 21 subject categories with resources being identified by a combination of both letters and numbers. For example, books on education are identified with a call number that begins with the letter 'L' and those on political science under 'J.' The number of categorization classes are not restricted, nor are the numerous subclasses included in the system.
Dewey vs. LOC - Clash of Classification Titans
So which system is better? That depends on the person you ask. Proponents of Dewey may suggest that the LOC system is 'impure' because, rather than being based on a taxonomy of knowledge, it was created to classify items from a single library. Some also believe that the letter-number system of identification is laborious and second best to Dewey's all numeric approach. Supporters also cite the system's reliance on facets (or groupings of related subjects) to organize materials.
Perhaps unsurprisingly, people who prefer the LOC have their criticisms of Dewey. Many perceive shortcomings of that system's ability to catalog items covering new subjects. For instance, computers weren't around when Dewey was developed and, as a result, weren't accounted for under the ten subject category headings. While the system has been updated over time, a closed taxonomy has forced computers and other tech topics to be shoehorned into a category labeled 'General.' (The LOC system, on the other hand, has annexed a 'Technology' subject heading.) Detractors of Dewey also suggest that its decimal system for identifying items leads to long call numbers that make identifying resources cumbersome, particularly in academic libraries with groupings of specialized topics.
While some librarians and other bibliophiles have a strong preference for either Dewey or the LOC system, many others concede that both systems have flaws and that libraries should follow practices that are best for their respective collections. Many public libraries, for example, continue to use Dewey while some academic libraries have made the switch to LOC to allow for greater specialization in identifying resources.
Still other librarians are forsaking both systems for more simplistic subject-based taxonomies typically found in bookstores. This move, made in response to perceived consumer habits, has many purists up in arms and has prompted initiatives to develop a hybrid system that is intuitive to users but still allows for detailed classification. Perhaps in the future, then, a new classification system heavyweight will emerge in this battle for categorization supremacy.