Classification Systems: Why Care?
- Classifications simplify our environment. When we divide up the universe of knowledge into classes or facets, we are sorting information objects into groups and into a system of relationships. This system helps us reduce chaos and confusion among the things that surround us. This highlights all the more the importance of classification systems as a way of dealing with information overload in the Information Age.
- Classifications reduce the load on our memory. Imagine having to remember the features and properties of entities and events as if they are purely distinct individuals unrelated to one another. We would have to deal with each and every instance as if we were encountering them for the first time. Fortunately, classifications provide a way for us to make explicit the natural groupings that we see in the world as well as those artificial groupings that we create to understand complexity better.
- Classification helps us store and retrieve information. This one is obvious enough to librarians and information professionals. The categories that we create become storage units into which we assign information resources and we use these units to name or label these objects so that we have a way of knowing where to retrieve them for use later.
- Classification helps us generate new knowledge. The storage and retrieval functions of classification tend to obscure the fact that our systems of classification become information in their own right. I would guess that many people have used library catalogs not only to find information but to use it also like a reference tool, which could show the relationships between topics, between authors, between works, etc. From these gleanings, we come to know what is there and what is not there and perhaps induce us to create what is not there yet.
From "Librarians and Classification: Defining a Middle Space of Social Responsibility" by Glenda Claborne.
About the Library of Congress Classification (LoC) System
Quick Facts
- Developed in late 19th century
- Favored by large universities and research collections
- LCC call numbers begin with a letter.
- The system divides all knowledge into 21 basic classes.
- The first letter represents the broad subject. For example, D is for History
- The second letter represents a narrower subject within the broad subject. For example DH stands for British History
- The next part gives a more precise definition of the subject matter. These are numerical.
- The final part refers to the author's name. It usually has a letter and a number.
2nd part of letters and numbers, not always present
Year of publication
Advantages
- New classes, subclasses, topics can be added
- Unique numbers can be assigned to a work.
- Cutter numbers are flexible
Disadvantages
- Large number scale
- Time lag between revision of schedules
- Classification dependent on acquisition of Library of Congress
About the Dewey Decimal Classification (DDC) System
Tip: The SRSU Library uses the DDC.
Quick Facts
- DDC call numbers begin with numbers
- Has ten main divisions that are further divided into more specific numbers.
- Conceived by Melvil Dewey in 1873 and published in 1876.
- First digit represents main class. For example, 500 represents science.
- The 2nd digit represents the division. For example, 510 for mathematics, 520 for Astronomy.
- 3rd digit represents each section. For example, 530 is the division within it are 531 for classical mechanics, 532 for fluid mechanics.
Advantages
- Numerical systems allows for ease of access across the world that may have a different language.
Disadvantages
- Parts of DDC are arranged by discipline not by subject, a subject may appear in more than one class. For example, clothing can fall under several disciplines. The psychology influence on of clothing is 155.95 (as part of the discipline of psychology) or in customs associated with clothing in 391.