Frequently, quantum mechanics is taught toward the end of the first year of physics -if it is taught at all. The reason for delaying the study is that quantum mechanics is a very abstract idea without much practical purpose. Therefore, students cannot understand it until they have learned all the rest of physics. We are challenging that way of thinking by creating instructional materials for quantum mechanics that can be integrated throughout the first physics course rather than just tacked on at the end. In addition, we have transferred some of the materials and the basic learning approach to higher-level courses. The result is a hands-on approach to learning and teaching quantum mechanics for a broad spectrum of students. We describe here some of our materials, as well as results of using these materials with students.

We investigated introductory physics students’ mental models of sound propagation. We used a phenomenographic method to analyze the data in the study. In addition to the scientifically accepted Wave model, students used the “Entity” model to describe the propagation of sound. In this latter model sound is a self-standing entity, different from the medium through which it propagates. All other observed alternative models contain elements of both Entity and Wave models, but at the same time are distinct from each of the constituent models. We called these models “hybrid” or “blend” models. We discuss how students use these models in various contexts before and after instruction and how our findings contribute to the understanding of conceptual change. Implications of our findings for teaching are summarized

In problem-solving situations, the contextual features of problems affect student reasoning. Using Newton's Third Law as an example, we study the detail of the involvement of contexts in students' uses of alternative conceptual models. Through research, we identified four contextual features that are frequently used by students in their reasoning. Using these results, a multiple-choice survey was developed to probe, in large classes, the effects of the specific contextual features on student reasoning. Measurements with this instrument show that the different contextual features can affect students' conceptual learning in different ways. We compare student data from different populations and instructions and discuss the implications.

We investigated students' mental models of sound propagation in introductory physics classes. In addition to the scientifically accepted wave model, students used the "entity" model. In this model sound is a self-standing entity, different from the medium, and propagating through it. All other observed alternative models are composed of entity and wave ingredients, but at the same time they are distinct from each of the constituent models. We called these models "hybrid" models. We will discuss how students use these models in various contexts before and after instruction.

The concept of potential energy diagrams is of fundamental importance in the study of quantum physics. Yet, students are rarely exposed to this powerful alternative description in introductory classes and, thus, have difficulty comprehending its significance when they encounter it in beginning level quantum courses. We describe a learning unit that incorporates a sequence of computer interfaced experiments using dynamics or air track systems. This unit is designed to make the learning of potential energy diagrams less abstract. Students begin by constructing the harmonic or square well potential diagrams using either the velocity data and assuming conservation of energy or the force-displacement graph for the elastic interaction of an object constrained by springs or bouncing off springy blocks. Then, they investigate the motion of a rider magnet interacting with a configuration of field magnets, directly and plot the potential energy diagrams using a magnetic field sensor. The ease of measurement allows exploring the motion in a large variety of potential shapes in a short duration class.

We investigated students' use of Newton's second law in mechanics and electromagnetism contexts by interviewing students in a two-semester calculus-based physics course. We observed that students' responses are consistent with three mental models. These models appeared in mechanics contexts and were transferred to electromagnetism contexts. We developed an inventory to help instructors identify these models and direct students towards the correct one.

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Using computer-mnnolled digital 'n IM1 the ~~~r c~~~~g i~~ &mme Bwner ameluded a discumion of innovative teaching mat&&& of tbe late video, studsnts con view and i98~)a 'by saying, m e i n t e m t of ~audi-ud] analyze the physics of events, as re But while film and videotape can in principle bring some of the knowledge and eqerienw of outatanding teachers into any elassmom, tbeg have amajw timitation. The control exercised by the elasmorn teacher or the student is limited to txmba the film on or off. Once the lilm or videotape is turned on, the flow of information is controlled by the film production team. Thus one of the I mosb i q a b n t capabilitiw of the experienced teaaherthe abili$y to respond immediately and appropriately to the nee& ofthe s t d e n b i s not available in these media Dean Zollman is a professor of physics at Kansas Stare Interactive video gives teachers a varietg of University, in Manhattan, Kansas. Robes Fuller is a professor a~d i o v i d materials and techniques that they can conof physics at the Untversity of Nebraska, Lincbln. tsol Should teaohem wish, they can pass that control to the students and 80 enable them to answer their own inquiries a t a pace that is comfortable for them. In many ways interactive video makes physics teachers a part of the media production and instructional design team even though they never visit a television studio. What is interactive video?In a generic sense interackive video is any video in which the user User more than minimal o n 4 contmI over what apon the video screen, including: b random access, which allows the user to select and display a segment or an individd frame (pietux4 -with minimal search time A2 PHYSI CS TODAY APRIL 1Wd nteracrive video makes possible fhe ddetlled study of &life events such as the motion of a pele-vaulter (a), the notien of a dummy during an auto crash (bi and the :olhapse of the Tacoma Narrows Bridge (c). Figure 1 b stiU frame, which allom any frame to be clearly &played for as long as the user wishes to view it b step firsme, which enables the user to display the next or previous Frame b slow play, which lets the user play the video at any We have been exploz'ing the use of intemtive videa in physics teaching since 1978. The approaches we have developed range from simple motivation of the study of a topic to detailed analysis of complex real-world events using mathematical and vjaual models.