A Model to Determine Optimal Numbers of Monograph Copies for Preservation in Shared Print Collections

Abstract

In this study we developed a model and a spreadsheet tool for calculating, based on user input informed by available data, the probability of at least one usable copy of a monograph title surviving at various time horizons in shared print collections. The calculation incorporates four risk factors, which were assigned values based on research in the literature and our own studies. We applied the model to sample selected time horizons and risk tolerances, which suggests a minimum number of copies of a title needed for retention.