Information technology has played several important roles in group decision making, such as communication support and decision support. Little is known about how information technology can be used to persuade members of a group to reach a consensus. In this dissertation, I aim to address the issues that are related to the role of visual representation technology (VRT) for persuasion in a forecasting context. VRTs are not traditional graphical representation technologies. VRTs can select, transform, and present data in a rich visual format that facilitates exploration, comprehension, and sense-making. The first study investigates conditions under which teams are likely to increase the use of VRTs and how the use of VRTs affects teams' consensus development and decision performance. The second study evaluates the effects of influence types and information technology on a choice shift. A choice shift is the tendency of group members to shift their initial positions to a more extreme direction following discussion. A choice shift is also called group polarization. To complement my first two studies, I conduct a laboratory experiment in my third study. I explore the effect of VRTs and team composition on a choice shift in group confidence.