The question of when to withdraw materials from libraries has gotten heightened attention lately.  Everyday readers may not always realize it, but most libraries get rid of books and other materials on a regular basis.  Libraries typically have limited space, but keep acquiring new materials to serve their audience’s needs.   As they acquire new materials, they typically make room by getting rid of materials that no longer serve their audience as well; this is variously known as “withdrawing”, “deaccessioning”, or “weeding”.

Some libraries weed more aggressively than others.  School and public libraries tend to turn over their collections more quickly than academic research libraries.  There’s not much value a middle-schooler can get out of an outdated science book, for instance, compared to a current one.  And a public library user looking for a book on how to use their new Windows 7 computer shouldn’t have to wade through stacks clogged with TRS-80 programming guides and the like.  You can find amusing anecdotes about books that have outlived their usefulness in these kinds of collections in the blog Awful Library Books, one of the blogs on LISNews’ 10 Librarian Blogs to Read in 2010.

Academic libraries typically don’t weed as aggressively.  The larger research libraries aim to have a broad selection of thought on subjects from various points in history, as well as whatever happens to be of current interest.   A book on science that no longer reflects current scientific understanding may still be useful for researchers that want to look at the history of science, or at how science interacted with culture at the time.  Even the peripheral details can be of interest; for instance the photographs in an obsolete computer guide can tell us what what the computers looked like, and how they were expected to be used.  The most interesting aspect of many old periodicals nowadays is often the advertisements, rather than the editorial content.

Especially when they’re digitized, large corpuses can also be of major interest even when the individual items might not be particularly noteworthy.  They can help you track the use and evolution of language, for instance, or quash unwarranted patents.  I’ve talked before about the great potential of Google Books and similarly comprehensive corpuses.

Even so, research libraries still get rid of materials, or move them to offsite warehouses, when space is short.  As more users access materials online instead of print, we often ship out print volumes that have online surrogates.  Recently Ithaka published a report called What To Withdraw that recommends gives guidelines for withdrawing materials that are online in sustainable archives (such as Ithaka’s own JSTOR), and that have a few physical copies in print archives somewhere.  Doing this responsibly may help many research libraries grow their collections, or repurpose their spaces, in useful ways.  Selling particularly valuable items to more appropriate libraries can also help fund additional library acquisition and activity.

Carefully considered, then, withdrawal can greatly benefit libraries and their users.  But libraries need to think not only about their own collection’s purposes, but about the systemic risks of individual library collection decisions.  For instance, many of the “Awful Library Books” justifiably withdrawn from public libraries might still be of historical research interest to someone.  Even if academic research libraries would keep them, many of the books intended for popular or specialized non-academic audiences were not collected by academic libraries in the first place.  If all the public libraries with these books simply throw them out, and no copy gets transferred to a library or archive with a longer-term interest, the materials may disappear forever.

Online access, as an alternative to retaining print copies, may not be as reliable as one expects.  Recently, the archives of many popular magazines that were available through various subscription databases became part of an exclusive deal from one database vendor.  This is likely to raise the costs of access to many libraries, both because they may have to subscribe to a new database to keep providing these magazines, and because the price of the new exclusive bundle is likely to increase.  But even if vendors keep prices reasonable, libraries’ own situations may change.  Here in Pennsylvania, funding to libraries has been cut severely enough that many now have to cancel subscriptions to heavily-used databases. The linked story has a heartbreaking quote from one of the public librarians that’s had to drop their formerly free Power Library subscription: “I got rid of [our old magazines] because everything was in the database.”

How can we insure against these sorts of cultural loss, even as we withdraw items?  A key principle is replication.  In the words of one well-known digital preservation program, “Lots of Copies Keep Stuff Safe”.  When we consider withdrawing something, we stop to think if some other library or institution might find it of value. If we’re considering dropping print originals for digital surrogates, we check to see if other institutions we trust are keeping the originals safe, or would be willing to do so.  We also make digital copies of print materials that may be at risk, and we try to spread around these copies as widely as practicality and copyright law allows.  And we develop and support efficient inter-library transfer networks so that we can quickly move locally deaccessioned materials to where they’re needed or valued.

Many librarians have a philosophy of public service that draws on Ranganathan’s famous set of Five Laws of Library Science, which includes principles like “every reader his book” and “every book its reader”.   As we try to preserve our broad cultural heritage in the midst of withdrawal, loss, and replication, a related principle, “Every book its libraries”, is a useful one to keep in mind.

[Edited slightly 4:12pm Jan 28, in response to a comment below: deleted struck-through text, and added italicized text]