and students' total buy-in. If students see the on-line assignments merely as an add-on to the course, to be completed perfunctorily in the shortest time possible and then discussed briefly at the beginning of class, before the "real" lecture, they will resent the extra work and will not get any additional benefit from JiTT. Teachers using JiTT report a spectrum of results, ranging from significant affective and cognitive gains to very negative student reactions, disillusionment, and sometimes a regression in learning gains. An example of successful JiTT comes from a five-semester study at North Georgia College & State University. This study analyzed responses from four force concept inventory (FCI) questions (the distractors as well as the correct answers) for evidence of students reaching the transition threshold from "common sense thinking to Newtonian thinking", a well-defined notion in physics education. Sixty-one percent of the students in the JiTT class reached the threshold, compared to only seven percent in the traditionally taught class. Marrs reported similar gains on pre-post assessment in biology, using the Hake metric, defined as (posttest% – pretest%)/(100% – pretest%). With traditional lecture-based pedagogy the gain was 16.7%; the gain jumped to 52.3% with JiTT and to 63.6% with collaborative learning. Since the introduction of JiTT at the US Air Force Academy, the final exam questions in the introductory physics sequence have shifted significantly towards conceptual probing for deeper understanding. Analyzing carefully kept records from the pre-JiTT early 1990s until the present, one finds that despite the increasingly more challenging questions, the scores have held steady and even improved in some semesters. When JiTT was introduced in introductory physics at IUPUI in 1996 course attendance increased from under 50% to over 80%. Instructors in other disciplines have reported similar results. Better attendance inevitably leads to fewer students dropping the class and an overall rise in grades. In JiTT Physics and in Biology courses at IUPUI the D/F/W numbers decreased from 40% to under 25%. JiTT can make a difference in student study skills. Students in Marrs' biology class credit JiTT to a significant decrease in cramming for tests. She asked her students "Did you put off studying for Biotech 540 and as a result 'cram' for Biotech 540 tests?" to her graduate students, and 34% answered yes. However, 62% of the class answered in affirmative to the question "Do you 'cram' for other courses that you have this semester?"