From their site:
IEEE VIS 2015 is the premier forum for advances in scientific and information visualization. This weeklong event convenes an international community of researchers and practitioners from academia, government, and industry to explore their shared interests in tools, techniques, and technology.
A full complement of research presentations, tutorials, workshops, panels, demonstrations, posters, and exhibitions make this conference one of the largest and most important gatherings of researchers and professionals who specialize in the visual analysis of data.
We invite you to participate in IEEE Visual Analytics Science and Technology (VAST), IEEE Information Visualization (InfoVis), and IEEE Scientific Visualization (SciVis), by sharing your research, insights, experience, and enthusiasm.