CLASS program was developed by Martin Nystrand at the Wisconsin Center for Education Research (WCER) for the in-class analysis of classroom discourse. It is a research tool used to build profiles of classroom interaction and to investigate the effects of classroom discourse on student achievment. Not to be confused with the University of Virginia's TeachStone pen-and-paper instrument first appearing in 2009 and used in professional development, CLASS is a research tool developed since 1988 under the auspices of three national research centers (The National Center on Effective Secondary Schools, 1985-90); the National Center on Organization and Restructuring of Schools, 1990-95; and the National Research Center on English Learning and Achievement, 1996-2001) and has been funded through to 2016 by the US Department of Education's Institute of Educational Sciences to develop a new version, CLASS 5.0, that will autonomously measure and assess key indices of classroom discourse. No observer or research assistant data collector needed, nothing intrusive in classrooms, no violation of teacher or student identity. Just a super smart phone app-like device and some microphones that autonomously process classroom discourse.
CLASS has been used in several large-scale empirical studies across the United States and was key to finding the first empirical support ever for the role of open-ended discussion in literature instruction. CLASS has become a stock in trade for much empirical research on classroom discourse and has been regularly cited in major published research papers as a key tool in the collection of classroom data.