Just-in-Time Teaching (JiTT) is a teaching and learning strategy comprised of two elements: classroom activities that promote active learning and World Wide Web resources that are used to enhance the classroom component. Many industries use Just-in-Time methods; they combine high-speed communications and rapid distribution systems to improve efficiency and flexibility. Our use of JiTT is analogous in many ways. We combine high-speed communications on the web with our ability to rapidly adjust content; this makes our classroom activities more efficient and more closely tuned to our students' needs. The essential element is feedback between the web-based and classroom activities. JiTT is a strategy that combines use of the web with a collaborative learning environment to improve student learning of and attitudes toward various content areas.