Improving Laboratory Courses

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Categories: GSI Online LibraryTeaching Effectiveness Award Essays

by Nicholas L. Pivonka, Chemistry

Teaching Effectiveness Award Essay, 2001

In the fall of 2000, when I found that I would be teaching chemistry 4B for a second time, I took the opportunity to identify two areas for improving the quality of the course and my teaching. One involved restructuring the laboratory portion of the course to make it more relevant and challenging, the other sharpening my methods for identifying and anticipating difficult course concepts.

I sought to improve the laboratory portion of the course by improving the quality of experiments the students were asked to perform. One of the experiments was clearly a candidate for replacement. The experiment, based on the solubility properties of metal salts, provided little intellectual challenge for the students. The procedures carried out were repetitious and taught the students no new analytical or technical skills. The students’ dislike of the experiment was obvious from the quality of their lab reports, and course evaluations contained many criticisms of the experiment.

Professor Ron Cohen gave permission to design a new experiment to replace the unpopular solubility lab. In its stead, I implemented a new flash photolysis lab. This was a significant improvement because the subject matter was relevant to both the course material and to modern research in physical chemistry. Also, the experiment required the assimilation of new ideas, including time dependent spectroscopy and kinetic analysis. This requirement alleviated the boredom brought about by the repetitive tasks of the solubility experiment and increased its inherent educational value.

My second emphasis was to improve the methods I used to identify and anticipate difficulties the students would have with the course material. I had found in my previous teaching experiences that difficulties with the subject matter were often concentrated in similar areas for many students. My challenge was to both better utilize the feedback mechanisms at my disposal and to try to identify new channels for identifying potential problem areas.

To improve existing feedback mechanisms I kept a count of the number of students who had difficulty with particular concepts presented in lecture, homework or the laboratory. By tracking the number and type of questions I was asked, as well as homework and exam problems that were missed, I was able to identify and address common problems earlier. Additionally, I changed my method of discussion preparation to include practicing every one of the skills and concepts to be learned by the students, instead of performing a cursory check to see if I remembered them. The distinction turned out to be quite important, as I found that practice would enable me to anticipate the troubles of students by actively remembering my own previous difficulties. This illuminated a feedback channel I had previously ignored. I used the information obtained to make more efficient use of my discussion time, concentrating on areas where I was able to anticipate student confusion.

The effectiveness of the experimental improvement was assessed through end of semester course evaluations, which contained no complaints about the new experiment, in contrast to the many received in regard to the experiment it replaced. Students were also observed to be more active and talkative when performing the experiment, assisting each other with the new methods they were learning. Additionally, my innovations in identifying and anticipating student difficulties led to my section consistently outperforming other sections on the midterm and final exams.