Demystifying the Library: Weeding

While most people know libraries purchase new books for their shelves, not everyone is aware libraries also regularly remove books from their shelves. When people find out libraries discard books, they might be confused, or they might be upset. But the removal of previously purchased and donated volumes from a collection–colloquially called weeding, more formally called deselection—is an important part of a library’s collection maintenance activities.  

The primary purpose of a university library is to support the teaching and research occurring at the institution. Over time, what is taught and what is researched changes; some existing programs are discontinued, while new programs are added. Faculty and graduate students begin doing research in new areas. The library needs to regularly review and renew its collections to ensure its materials are meeting the current needs of students and faculty. One process for doing this is through adding new materials to the collection. The other process is by removing materials from it. 

Weeding means evaluating the items in a library’s collection based on certain criteria and then deciding whether to retain or discard items. The criteria used for removing something from the shelf can include: 

• Age – This is a big one. Generally speaking, the older the information is, the less relevant and useful it is to library users. This is especially true in rapidly changing disciplines like law, the physical sciences, health and medicine, and computer science (Windows 98, anyone?). Obsolescence is much less of a factor in the arts and humanities. 
• Usage – Libraries collect a lot of statistics about how often their collections are used, and if a book is shown to have not been checked out by anyone for an extended period (which can extend to decades) it might be a candidate for deselection. Usage and (old) age typically go hand-in-hand when it comes to weeding decisions. 
• Condition – When a library staff member discovers a damaged book on the shelf, there is a decision to make. If the book is still useful to the library’s users it can be repaired, or a new copy can be purchased. But if the damaged book is considered no longer of value to the library’s users, it will be discarded.  
• Newer editions – Many academic titles are published in multiple editions. As new information comes to light or as the topic changes, the original edition is revised and updated a second or a third or an eighth time. A library may decide to keep only the most recent edition of a title since it contains the most current information on the topic. 
• Electronic access – In the past ten years, many books have become available in electronic format. As teaching and learning move increasingly online, and as users increasingly seek information online, older print titles age, eventually becoming candidates for weeding.  

Weeding projects can take the form of occasional or ad hoc work, as the need for adjustments to the collection is discovered, or they can be larger-scale initiatives. In either case, a librarian will select a collection area (typically related to his or her area of subject expertise and responsibility) and review the items on the shelves using the criteria above. Depending on the scope of the project, this work can take days or months. The reasons for undertaking a weeding project include:  

• Providing a collection which matches library users’ current interests and needs 
• Ensuring the library’s materials are up to date 
• Removing outdated materials and information from the collection 
• Removing worn and damaged materials from the shelves 
• Creating space on the shelves for new purchases 
• Making navigation and use of the collection easier  
• Reducing physical shelving to allow new uses of the space (e.g., more seating). 

A weeding project is also a great way for the librarian to gauge the strengths and weaknesses of a collection. A hands-on project like this is essentially a review of the materials on the shelves, and it shows the librarian where a collection needs attention, either in the form of removing outdated materials or in purchasing new ones.  

It isn’t the role of most libraries to indefinitely retain every item purchased. While some libraries have been charged with preservation of the scholarly record and, therefore, never discard materials (the Library of Congress is the best example of this kind of library, though many very large university libraries have the same charge), most libraries are simply charged with meeting the needs of their user communities. And since user needs and preferences change, and because libraries have a finite amount of shelf space for their collections, weeding is a regular part of their activities.   

So, what happens to the books removed from the CMU Libraries’ collections? Our weeded books are first offered to Better World Books, a nonprofit book dealer who helps connect used books with people who want them. If Better World Books does not accept a book (because it’s deemed unlikely to find an audience through the service), the book is recycled.  

Libraries have been compared to gardens by many people. Even the word for removing materials from a library’s collection–weeding—comes from gardening vernacular. Both libraries and gardens contain desirable things and things that are not needed or wanted. And both libraries and gardens require regular attention and upkeep to ensure they are providing their users with the greatest possible benefit.