About the Authors

Kevin W. Boyack

kboyack@mapofscience.com

Affiliation SciTech Strategies, Inc., Albuquerque, New Mexico, United States of America

David Newman

Affiliations University of California Irvine, Irvine, California, United States of America, NICTA Victorian Research Laboratory, Melbourne, Australia

Russell J. Duhon

Affiliation School of Library and Information Science, Indiana University, Bloomington, Indiana, United States of America

Richard Klavans

Affiliation SciTech Strategies, Inc., Berwyn, Pennsylvania, United States of America

Michael Patek

Affiliation SciTech Strategies, Inc., Berwyn, Pennsylvania, United States of America

Joseph R. Biberstine

Affiliation School of Library and Information Science, Indiana University, Bloomington, Indiana, United States of America

Bob Schijvenaars

Affiliation Collexis, Inc., Geldermalsen, The Netherlands

André Skupin

Affiliation Department of Geography, San Diego State University, San Diego, California, United States of America

Nianli Ma

Affiliation School of Library and Information Science, Indiana University, Bloomington, Indiana, United States of America

Katy Börner

Affiliation School of Library and Information Science, Indiana University, Bloomington, Indiana, United States of America

Competing Interests

The authors have the following interests to declare: Authors Boyack, Klavans, and Patek are all employed by SciTech Strategies, Inc.; author Schijvenaars is employed by Collexis, Inc. No patent or product based on this work is under development. This commercial affiliation does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials. Data from this study are available for download at http://sci.slis.indiana.edu/sts/.

Author Contributions

Conceived and designed the experiments: KWB RK KB. Performed the experiments: KWB DN RJD MP JRB BS AS NM. Analyzed the data: KWB RK KB. Contributed reagents/materials/analysis tools: KWB DN RJD MP JRB BS AS NM. Wrote the paper: KWB DN RJD JRB BS AS KB.