He was formerly a staff scientist at the Los Alamos National Laboratory and an Assistant Professor at the Department of Computer Science of Old Dominion University. He obtained his PhD in Psychology from the Vrije Universiteit Brussel in 2001. Bollen has published over 70 peer-reviewed papers on problems in web science, social media analytics, sentiment tracking, digital libraries, informetrics, and computational social science. His research has been funded by the Andrew W. Mellon Foundation, National Science Foundation, Library of Congress, National Aeronautics and Space Administration, IARPA, and the Los Alamos National Laboratory.