About the editors JAKOB NIELSEN, PhD, is a distinguished engineer in the human factors engineering department of SunSoft. Dr. Nielsen's earlier affiliations include the IBM User Interface Institute at the T. J. Watson Research Center in Yorktown Heights, N.Y., the Technical University of Denmark, and Bellcore (Bell Communications Research). Nielsen coined the term "usability inspection" and is also the co--inventor of the heuristic evaluation methods described in this book. He is on the editorial boards of ACM Interactions User Interface magazine, Behaviour & Information Technology, Hypermedia Journal, Interacting with Computers, International Journal of Human--Computer Interaction, and International Journal of Human--Computer Studies. Jakob Nielsen is also the vice chair for publications of the Association for Computing Machinery Special Interest Group on Computer--Human Interaction. ROBERT L. MACK, PhD, is a Research Staff Member at IBM's Thomas Watson Research Center in New York, where he manages a usability engineering group in the Computer Science Department. Dr. Mack's research interests have focused on advanced user interface technologies - such as IBM's Common User Access graphical user interface guidelines - and development of methods for supporting usability engineering, including qualitative user interface methods such as thinking aloud, competitive benchmarking, and usability inspection methods. Dr. Mack has pursued many of these research interests while working with IBM development groups, and as a member of the IBM User Interface Institute between 1985 and 1992. He has taught courses on usability engineering and user interface design within IBM for a number of years.