The General Chemistry Course Driven by the ... - ACS Publications

tober 19, 1996, for high school, college, and university ... lege of the Holy Cross, and Nicholas K. Kildahl, Depart- ... Discovering Chemistry at Hol...
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Chemical Education Today

Conference Report: WPI The General Chemistry Course Driven by the Laboratory by Herbert Beall Most teachers of chemistry agree that the general chemistry laboratory plays an essential role in teaching our experimental science. There is not so much agreement, however, on what role the laboratory should play. Quite typically, the laboratory follows the lecture with the intention of reinforcing the concepts that have already been covered in the classroom. There are cases where the topics of the classroom teaching and the laboratory work have drifted away from each other, and the primary role of the laboratory becomes teaching chemical techniques. In the opposite approach, the discovery approach, the laboratory drives the course. Concepts are initiated by student experi…a question is posed in the mentation, and discussion room and the students then these concepts are exas a group design a plan to arrive panded in the classroom. at an answer to the question. Discovery learning was the topic for the Tenth Annual Worcester Polytechnic Institute Conference on Chemical Education held on October 19, 1996, for high school, college, and university teachers of chemistry. The speakers for this conference

were Richard S. Herrick, Department of Chemistry, College of the Holy Cross, and Nicholas K. Kildahl, Department of Chemistry, Worcester Polytechnic Institute. Herrick’s presentation was entitled “Reflections on Discovering Chemistry at Holy Cross”. He described a mature discovery laboratory program that was initiated in 1989 and involved all faculty in the department. Building renovations had been performed to provide

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Vol. 74 No. 2 February 1997 • Journal of Chemical Education

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Chemical Education Today

Conference Report space especially suitable for discovery learning, with laboratory, discussion room, and instrument room directly adjacent to one another or readily accessible. The major instruments (atomic absorption, UV-visible, Fourier transform infrared, and gas chromatography–mass spectroscopy) were selected to produce data quickly, making it practical for individual students to measure different data points …students feel the thrill and pool their data to construct meaningful graphs. of discovery… In a typical learning period, a question is posed in the discussion room and the students as a group design a plan to arrive at an answer to the question. The students then do experiments in the laboratory to develop hypotheses and test them. After this is completed, they return to the discussion room to draw conclusions. The experiments are carefully designed so that at the beginning of the exercise, it is not clear to the students what the results of the experiment will be or where the discussion will lead. The experiments are not open-ended but rather are intended to guide students through a laboratory exercise that will promote discussion and allow the reaching of conclusions. Herrick described a simple experiment involving the masses and densities of pennies. It was notable that thorough discussion of even such an elementary exercise developed many concepts: uncertainties, intensive and extensive properties, scientific method, and graphing linear equations. Benefits of the discovery laboratory approach include fostering learning in and out of

the classroom, providing a less threatening environment for students with different backgrounds, connecting lectures and laboratories, and teaching critical thinking. Problems with this approach include greater use of faculty time, scheduling problems because time blocks are longer, and lack of commercial resources. Herrick concluded by giving his view of the components necessary for a new discovery laboratory program: (i) development is necessary to adapt to a specific site, (ii) departmental consensus is required, (ii) whole-scale change works better than piecemeal change, and (iv) modern instrumentation is highly desirable. The title of Kildahl’s presentation was “Discovery Learning: Fact or Fantasy?” He expanded on the discovery approach as being suitable to the laboratory alone, the classroom alone, or linking laboratory and classroom. For example, in the classroom students can be presented with data and then participate in a guided discussion to find patterns in the data and generalize concepts from the patterns. As a simple example, pressure–volume or volume–temperature data can be presented with the aim of deducing Boyle’s or Charles’s law. Key aspects of discovery learning are students build their own understanding, classroom learning becomes interactive, the actual process of science is approximated, students feel the thrill of discovery, and more of the effort of learning is placed on the shoulders of the students. In the panel discussion that followed, there was a clear interest in using this kind of learning in high school and college chemistry classes, but there was also concern about the effort and expense involved. Herb Beall is in the Department of Chemistry, Worcester Polytechnic Institute, Worcester, MA 01609.

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Journal of Chemical Education • Vol. 74 No. 2 February 1997