Case-study descriptions of secondary and middle school classrooms in diverse contexts provide examples of how teachers implement connected classroom technology to facilitate formative assessment in science instruction. Connected classroom technology refers to a networked system of handheld devices designed for classroom use. Teachers were surprised at the knowledge they gathered about student learning in connected classrooms. They recognized that their students were better informed about their own learning and believed that use of the technology increased student engagement in on-task behavior. Connected classroom technology reduced barriers for formative assessment and informed teachers and students about classroom learning achievements and challenges. (Contains 4 tables and 1 figure.)