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.
The plan of this project was to combine a conventional lecture presentation with either a live or taped demonstration, followed by a short cooperative learning exercise intended to reinforce the relationship between problem type and physical concept.
The project involved a general chemistry course, which serves mainly science majors and pre-professional students. The lecture is presented to approximately 100 students, who meet three times per week in a lecture hall with auditorium type seating. This classroom includes a multimedia workstation, which was assembled by Dr. John C. Kotz (Chemistry Department, SUNY Oneonta). The workstation consisted of a Tandy model 1200 HD microcomputer, a Pioneer model LD-V4200 laserdisk player, and a Sharp model QA-25 overhead projector palate to display the screen image of the computer screen. Laserdisk and videotape images could be projected simultaneously on a large central screen as well as smaller TV monitors attached to the walls about one-third of the way back in the room.
The major software package used was KC-Discover (JCE: Software, Department of Chemistry, University of Wisconsin, 1101 University Ave. Madison, WI 53706) which acted as a controller for one of the laserdiscs, provided an electronically searchable database of information about the chemical elements and produced graphs of this information. The other main piece of software was a Lotus-type spreadsheet. The estimated price of the entire outfit, both hardware and software, was approximately $4000.
The plan was that approximately every 15 to 20 minutes the lecture would be interrupted by a visual presentation lasting about two to five minutes. These presentations might be videotapes, laserdisk images, KC Discover graphs, computer simulations, or live chemical demonstrations. In each case, the presentation was chosen to illustrate a concept just discussed in lecture. The relationship was then reinforced by a cooperative learning exercise done by pairs of students. This sequence of events was repeated throughout the fifty minute period.
The cooperative approach followed closely the ideas presented in Johnson, Johnson, and Smith's text (1991). Student pairs ("lecture partners") were formed informally at the beginning of each period. Most students soon found permanent partners, and so it required only a very short time at the beginning of each lecture to pair up students whose partner was absent. An unexpected benefit of this approach was that a number of students, especially commuters, commented that they felt less isolated and were more likely to study with the partner they had come to know well during the class.
To emphasize the parallel nature of the material, the students were instructed to write the regular notes on the right hand page of their notebooks, and observations, predictions and cooperative exercises on the left hand page. The lecturer emphasized that the material on the facing page was not less important but rather was a demonstration of the concepts on the right. This point was further stressed by asking examination questions that were based primarily on the left hand page notes.
Although each cooperative exercise used a unique script, most fit into a small number of categories. Observation questions asked students to describe what they had seen and explain it in terms of the preceding lecture material. In some cases, the cooperative work came before the demonstration, and students were asked to predict what was going to happen. Finally, they might be asked to practice a problem type which had just been discussed, using data from a demonstration. These three types of exercises were indicated by calling the left page the OPPs page, for observation, prediction and practice.
Following the live or multimedia demonstration, the students were called upon to answer the questions in the cooperative exercise script. To provide accountability, the instructor made it a point to address questions to any pairs who didn't seem to be participating, and frequently when one member of a pair answered correctly, his or her partner was asked to explain the answer. Thanks to this encouragement, almost all of the students participated in each exercise. It was further noted that the student interaction continued even after the lecture phase was resumed. This give and take not only allowed the students to find answers for many questions that could normally not be raised vocally in a large lecture, but also made the students more active participants in the process.
The use of computer simulations is worthy of special comment. Modern computer spreadsheets make it relatively easy to build simple simulations of many chemical concepts. The rapid response of this software makes it easy to do inquiry learning by comparing student predictions with spreadsheet projections. Even more important, the graphical display possible with spreadsheets seemed to make even complex concepts more understandable.
The final step in the process was to include some questions based on the demonstrations and cooperative exercises on the examinations. This is essential because it both continues to emphasize the relationship between concepts and problem types and also further validates the instructor's assertion that the two types of notes are equally important.
It's apparent that this combination of steps was somewhat more time consuming than a conventional lecture presentation of the same material, but the disparity is not as great as might be expected. Indeed, for instructors who have previously used many live demonstrations and spent significant amounts of class time attempting to clarify the student's understanding of basic concepts, the amount of extra time is more than compensated for by the positive aspects of the method.
The ideal method of evaluation would be to compare the results of this project with a control group of students who were taught in a more traditional way. Unfortunately, it was not possible to do this; however, several measures indicated that there had been improvement. The number of failing grades on the first exam and the number of course withdrawals were both down significantly. Even though there are surely biases that affected the results, these positive results were very heartening.
From the instructor's point of view, the course seemed to deal more with chemical concepts and less with math. There is some justice to the student complaint that general chemistry is "just an applied math course." Solving mathematical problems is, indeed, an important part of learning chemistry, but there is a real need to change the emphasis, so that chemical concepts occupy the central position, and the problems are merely demonstrations of the concepts. Non-mathematical problems also play a key role in chemistry, and this method not only placed more emphasis upon these situations but also better prepared students to handle this challenge.
At the end of the year-long course, the students were asked to respond to a series of statements using a five-value Lickert Scale. The results are show in Table 1. As might be expected with this generation, video presentations were very popular, but in every case, the students indicated that these methods made the course more enjoyable and also made the material easier to learn. The very small number of negative responses TABULAR DATA OMITTED was especially heartening. The survey also gives some indication that the use of lecture partners continued outside of class in study groups and other informal arrangements.
Students who know they are involved in this type of study are normally expected to respond favorably to the attention which they receive, and part of the positive response may be due to this factor. On the other hand, the combination of new teaching methods and unfamiliar technologies often produced difficulties. These classroom glitches, however, do not seem to have produced negative student evaluations.
Success was also measured based on examination performance, but the outcome was ambiguous. Fewer students failed the first two examinations of the semester than had been the case during the previous two years, even though the difficulty of the examinations was, as far as could be determined, very similar. Also, far fewer students withdrew from the class. Comparison of the results of multiple choice questions identical with those given four or five years ago may have also indicated better performance.
On the other hand, the results were less favorable on the third examination and the final, and the number of students who failed the course was higher than in recent years. In part, this decrease is probably because the lower withdrawal rate caused students, who in previous years would have been gone before the third examination, to remain in the course to the end. Comparison with previous years may be difficult, but it seems safe to say that student performance was at least roughly equivalent to that obtained in previous years with a more traditional approach.
In summary, student enthusiasm for the course increased, chemical concepts were placed on a more equal footing with mathematical problems, more descriptive material was added to the course, and student performance on the material equivalent to that emphasized in the past was at least as good as it had been in previous years. These successes are encouraging, considering that the course revision was still far from complete.
During the 1991-2 academic year, considerable progress was made towards implementing the course design described earlier. A large number of cooperative learning exercises were introduced, and the instructor began to feel relatively comfortable about leading them. The number of live demonstrations was increased significantly, and many short video clips, both tape and laserdisk, have been added. The conversion has not affected all of the lecture units equally, but since neither released time nor extra support was available, the amount of progress was probably as much as might have been expected.
Much remains to be done, especially on the computer simulations. These seem to be an especially powerful tool, but they require a great deal of preparation. A number of new laserdiscs, video tapes, and other special computer software programs have been obtained this year and are currently in the process of being worked into the course plan. In the fall of 1992, a new multimedia workstation became available, based on a Macintosh SE30. In the long run, this will surely be a beneficial change, but it will require some time to become accustomed to the new system, and much of the software previously used must now be replaced.
Student response to the multimedia presentations was very enthusiastic, as might be expected. Perhaps one of the more significant observations from this project is that multimedia can be used successfully even in the absence of expensive equipment or an extensive support staff. The videos offered many advantages, including the ability to safely show dangerous reactions, to show processes which would otherwise be too small to be seen in a large room, and to rapidly repeat a demonstration when necessary. These advantages, in combination with the favorable evaluations, seem to justify continued development of this aspect of the project.
Cooperative learning was probably the portion of the study which required the least outside support and extra effort, even though one should not underestimate the commitment needed for an instructor to change a teaching method which has been in use for many years. The beneficial results noted here, including increased student involvement and greater focus on chemical principles, indicates that lecture partners, or some similar method, can be a valuable technique, even in a large lecture.
It's still too early to determine whether this combination of techniques will affect the way students solve problems. It seems reasonable that if the presentation knits together the concepts with the accompanying problem types by means of cooperative exercise and also reinforces this relationship by extensive use of live and recorded demonstrations, it represents a potentially powerful method of inducing students to form a stronger mental association between the concept and the problem type. As the current project is continued, one of the goals will be to seek ways to determine whether or not this assumption can be confirmed in the classroom.
The initial results of this project suggest that important benefits can be obtained by combining multimedia presentations, cooperative learning, and traditional techniques into a unified system. The resulting environment encourages student involvement and is a valuable support for inquiry learning.
The author wishes to express his special appreciation to Dr. Nelson Dubois and Dr. Joseph Tausta, both from SUNY Oneonta, who have freely provided so much encouragement and help as the project proceeded. He also acknowledges the help of Dr. John Kotz, Chemistry Dept., SUNY Oneonta, who designed the multimedia workstation used in this project, and the Saunders College Publishing Co., who provided some of the videotapes and disks.
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Dr.Harry E. Pence is Professor of Chemistry at SUNY College at Oneonta.…