@device(postscript) @libraryfile(Mathematics10) @libraryfile(Accents) @style(fontfamily=timesroman,fontscale=11) @pagefooting(immediate, left "@c", center "@c", right "@c") @heading(Mobile Information Access) @heading(CMU-CS-96-107) @center(@b(Mahadev Satyanarayanan)) @center(January 1996@foot) @center(FTP: CMU-CS-96-107.ps) @blankspace(1) @begin(text) The ability to access information on demand when mobile will be a critical capability in the 21st century. In this paper, we examine the fundamental forces at work in mobile computing systems and explain how they constrain the problem of mobile information access. From these constraints, we derive the importance of adaptivity as a crucial requirement of mobile clients. We then develop a taxonomy of adaptation strategies, and summarize our research in application-transparent and application-aware adaptation in the Coda and Odyssey systems respectively. @blankspace(2line) @begin(transparent,size=10) @b(Keywords:@ )@c @end(transparent) @blankspace(1line) @end(text) @flushright(@b[(15 pages)])