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Models for Shelf Reading

Though unshelved books are a problem in every library, little systematic effort has been made to design an optimal solution. I here present a mathematical model in an attempt to approach such a solution. This model tries to minimize user frustration consistent with restrictions on the number of hours available for shelf reading. Resulting from this model is a schedule in which each section of the collection is assigned its own shelf-reading frequency. The properties of the solution are discussed, and a simple example of its use is given. Next, a decision procedure is outlined that determines how much time should be set aside for reading shelves. The method is to find a point where the cost of reading shelves is balanced by the costs resulting from misshelved books; in this paper these are the costs of searching for lost books and buying additional copies of books which could not be found. A test is suggested to determine whether a library's shelf-reading policy is optimal. The paper concludes with a discussion of possible extensions of the model. The approach taken applies to any file in which misfilings are a problem; this paper treats the book collection as an example of such a file.