Purpose

Ask former students of introductory chemistry to describe their experiences in the laboratory and their answers are likely to include groans of remembered boredom. Hardly ever is the first encounter with Bunsen burners and pH meters recalled as an exciting initiation into experimental science.

The reason for this common attitude is that, traditionally, beginning chemistry laboratories have been attempts to illustrate principles rather than true experiments. Dependent on memorization and requiring little thought from students, these exercises succeed one another weekly throughout the semester, every technique seemingly an end in itself and with little relevance to any broader concept or purpose.

The goal of this project was to convert the general chemistry laboratory into a place where the metamorphosis from student to scientist can begin as the learner solves problems, evaluates and interprets data, and designs and carries out experiments.

Innovative Features

With help from the National Science Foundation as well as FIPSE, the project director redesigned the existing series of 12 one-period laboratory exercises into a research-oriented program where students work in groups on three laboratory projects during the course of a semester. As they carry out the projects, which include identification of an unknown compound, thermochemistry, identification of an organic unknown, analysis of a mixture, electrochemistry, and analysis of colas by spectroscopy, students learn essential laboratory techniques in addition to problem solving, collaboration, and written and oral communication.

Students are assigned to groups of four for the entire semester. The groups are as heterogeneous as possible for gender, race, and age. Each student plays a given role, e.g., leader, recorder, etc., and changes roles with each project.

The projects are open ended. With the teaching assistant's help and in cooperation with members of their group, students devise and control their own experiments. If they need to synthesize a compound, for example, they must decide on the reaction to be performed, calculate the amounts of reactants to use, and determine reaction conditions.

Each group works on a separate but related project. For example, in the role of researchers working for the Environmental Protection Agency, students are asked to identify a compound that has been found in a landfill, find out its properties and synthesize it. Each group is given a different compound, which requires students to develop a different plan of action, although the groups use the same experimental techniques.

Students learn techniques in the context of the experiments they design. SuperChemLab, a multimedia Hypercard-based program, contains audio, video and text clips illustrating laboratory techniques. If, for example, students need to learn how to perform a titration, they can access the appropriate video and text from the "techniques" screen. However, if students do not know when to perform a titration, the program leads them to instructions on when and how titrations are done by posing a series of questions.

In order for this hands-on, cooperative pedagogy to work teaching assistants had to abandon their instructor role in favor of functioning in a coaching and advising capacity. This required a major training effort, involving an initial workshop on cooperative learning-covering topics from gender speech patterns to appropriate ways of responding to students-and weekly meetings throughout the semester.

Evaluation and Project Impact

One half of the 1,300 students enrolled in beginning chemistry were randomly assigned to traditional laboratories and the other half to cooperative laboratories. Their attitudes toward chemistry and the laboratory experience were surveyed through a laboratory evaluation form, and their final examination grades in the lecture section of the course and their retention rates were compared.

The differences between the two groups' responses to the laboratory evaluation were not large. Nevertheless, students in the cooperative laboratories tended to be more positive about their experience than their peers in traditional laboratories.

Because the same lecture examination was administered to all students, it was possible to determine whether a correlation existed between performance in the lecture examination and the type of laboratory attended. The cooperative laboratories were not specifically designed to reinforce the lecture material, and they covered skills that were not stressed in the lecture course. Thus, there was a good possibility that the grades of students in the cooperative laboratories would suffer.

In the first analysis, the type of laboratory seemed to have little effect on lecture examination scores. When the scores were analyzed by gender, however, women in the cooperative laboratories outscored women in the traditional sections by an average of eight points. A two-tailed t-test indicated that this was a significant difference in the scores. A smaller rise in the scores of the male students was not statistically significant.

A similar difference appeared in retention rates. Whereas women in the cooperative laboratories dropped the course at a rate of 13 percent, the rate for women in traditional laboratories was 22 percent. Men in both kinds of laboratories dropped the course at a rate of nine percent.

Project Continuation

The cooperative laboratories have been fully integrated into the curriculum and have replaced the traditional sections.

Recognition

The project has been presented at a number of conferences and workshops as well as in journal articles. An instructor's guide and laboratory manual have been published by McGraw-Hill, and SuperChemLab, a multimedia Hypercard application for laboratory techniques and methods, is available from Falcon Software.

Available Information

For further information, contact:

Melanie M. Cooper
Department of Chemistry
Clemson University
Clemson, SC 29634
Telephone: 803-656-2573

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