On the national level, several factors have recently combined to cause a re-evaluation of the instructional methods used for introductory science courses. Critics such as Sheila Tobias (1990) have argued that current instructional approaches unnecessarily discourage interest in science by women and members of minority groups. The technology required for combining sound, animation, and video images in a multimedia lecture format has become available in forms which require only modest investments of time and money. Cooperative learning methods have become better understood and more widely used. Finally, improved understanding of the learning process has suggested new ways to integrate all of these developments into a coherent, effective educational approach. Each of these developments has affected the project described in this article.
These national trends have been reinforced by certain developments at SUNY Oneonta. Declining numbers of majors, decreased student performance (at least as indicated by some measures), and the desire to make science more accessible to women and minorities have prompted the exploration of new teaching techniques.
A major stimulus for change was the expectation that using more visual imagery in class would help to improve the student's observational ability and proficiency at visualizing chemical principles. This skill is extremely important for chemists, since the level of professional development in this field is closely related to the sophistication of the mental imagery which is used (Kleinman 1987).
In addition, seeing the principles demonstrated in class should make it easier for students to understand the connection between problem solving and physical concepts. There is considerable research indicating that many students in introductory physical science courses fail to see a relationship between problem solving and the physical principles upon which problems are based. There are various names for this problem, means-ends analysis (Larkin, 1980) or the Roladex approach (Bunce, 1991), but the research indicates students focus predominantly on manipulation of the symbols to produce the required answer without referring to the physical principles upon which the problem is based.
The traditional method of showing physical concepts in chemistry classes is lecture demonstrations, but several recent developments deter this practice. Liability questions discourage the use of demonstrations that offer any risk; increased teaching loads and the desire to cover more topics in the introductory course leave less time to set up and perform demonstrations, and the size of many classes is so large that many important reactions are too small to be easily seen.
Some have sought to solve the problem by totally substituting multimedia presentations for the lecture, but these efforts have not always been successful. For example, a recent attempt to use microcomputers to teach organic chemistry (Casanova 1991) found that student involvement and interest was increased, but students taught in a conventional fashion still performed better on examinations. The reason for this is not clear. It may have been that students had to absorb a greater amount of data during a multimedia presentation, or it may have been that approach made it too easy for them to become passive participants, who failed to assimilate the information presented.
This paper describes a project which combines several different educational methods. First, the visual imagery was integrated into a traditional lecture format, so students had clear guidance to help unify the various components. Second, the students used cooperative learning techniques to explore what they had seen, arrive at observational generalizations, and make predictions. This combination of lecture, multimedia, and cooperative learning was both popular with the students and seemed to create a productive learning environment. …