<!doctype html public «-//w3c//dtd html 4.0 transitional//en»> http-equiv=content-type> Accessibility is never a given – it degrades over time and must be recreated or maintained. Diverse mechanisms govern the accessibility of information over time, including social trends as well as processes of loss, preservation, selection, and recovery. This book develops an interdisciplinary view on the long-term accessibility of information.