1 Shared Files – The Retrieval Perspective Ofer Bergman 1 Bar-Ilan University, Israel Dept. of Information Science, Bar-Ilan University, 52900, Israel Tel: 972-52-358-3842, Fax: 972-3- 7384027 Email: oferbergman@gmail.com Steve Whittaker University of California at Santa Cruz Psychology Dept., University of California at Santa Cruz ,CA 95064, USA Tel: 1-831-459-2390 Email: swhittak@ucsc.edu Noa Falk Bar-Ilan University, Israel Dept. of Information Science, Bar-Ilan University, 52900, Israel Tel: 972-52-607-1995 Email: noa.falk@gmail.com This is a preprint of an article accepted for publication in Journal of the American Society for Information Science and Technology copyright © 2013 (American Society for Information Science and Technology). 1 Corresponding author.