You may have noticed signs in the library asking people not to reshelve books and journals after using them, but rather to leave them on a cart, or by the copier. Lots of people assume this is because we don't trust you to put things back in the proper order. While the Library of Congress call number system can indeed be a deep mystery to the uninitiated, there is actually a second and more crucial reason why we ask that you leave materials for us to reshelve.
Before we reshelve library materials left for us by our users, the library scans each item to indicate that it has been used. This usage data helps inform us when making decisions about whether to renew or cancel materials, or buy more items in a given subject area. (See, for example, the library's current review of journal titles costing more than $1000 per year.) So, *not* reshelving your favorite book or journal is actually a way of letting us know that it's important to you.
We pick up, scan, and reshelve materials at ISEL several times per day. If you ever have trouble locating an item in the library, please come see us at the Circulation or Reference Desks. We are often able to locate materials that seem hopelessly lost (another one of those great library mysteries).