The Exploratorium is a museum of science, art and human perception located in San Francisco. The Exploratorium''s Teacher Institute (TI) has been the professional development home for middle school and high school math and science teachers since 1984. TI's mission is to create and support a collaborative community of teachers, at all levels of their careers, through professional development that joyfully emphasizes the teaching and learning of science as a process for understanding the world around us.