31 Chen, Chaomei 2005 jul visualization problems, usability issues, education The author presents a revised and extended version of the top unsolved problems of information visualization that he outlined in an IEEE Visualization 2004 panel. These problems are not necessarily imposed by technical barriers; rather, they are problems that might hinder the growth of information visualization as a field. The first three problems highlight issues from a user-centered perspective. The fifth, sixth, and seventh problems are technical challenges in nature. The last three are the ones that need tackling at the disciplinary level. http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/mags/cg/\&toc=comp/mags/cg/2005/04/g4toc.xml\&DOI=10.1109/MCG.2005.91