From May 28 to June 1, 2007, a seminar on "Information Visualization - Human-Centered Issues in Visual Representation, Interaction, and Evaluation" took place at the International Conference and Research Center for Computer Science, Dagstuhl Castle, Germany. One important aim of this seminar was to bring together researchers and practitioners from Information Visualization and related fields, as well as from application areas, for lively discussion and interaction. The seminar allowed critical reflection on actual research efforts, the state of field, evaluation challenges, and other important topics. This report summarizes the event.