Edgord F. Bertout University of Detroit Detroit, Michigan
Graduate Assistants as Instructors for Open-end Laboratory Experiments
The use of open-end laboratory experiments in general chemistry has been described by Jay A. Young,' who has also written the most generally available text for this type of c o u r ~ e . ~To date the text and the approach have been successfully used in small colleges and in honors sections of large universities. In both cases however, each laboratory section and discussion period has been taught essentially by full-time, permanent staff members. It is the purpose of t,his paper to report on the successful use of Young's t,ext with a one semester, multi-section, lecture-lab course where all laboratory sections are taught by graduate teaching assistants. The text has been used for three semesters with a total of 65 sections of not more than 20 students. Each section meets each week for a three-hour laboratory period and a one-hour classroom discussion period. Both meetings of a given section are conducted by the same graduate assistant. Working in pairs, the students require about one and one-half lab periods per experiment. The graduate assistants who teach the laboratory sections are all 11s candidates. They are n~ostlyfirst. year students completely inexperienced with the openend approach. As such they are fascinated by the text, but in the beginning more than a little appreheusive about its use. To provide guidance therefore, one-hour staff meetings are held each week. For the first few meetiugs of each fall term, selected assistants are assigned to do problems from the text in the laboratory and report on them during the meeting just. as a student would do during his laboratory discussion period. The rest of the assistants are then encouraged to comment as the class is expected to do. By proper prompting, the instructors soon catch the spirit of the approach and then carry this back to their own students. The supervising professor then makes visits of decreasing frequency to each instructor's classes and laboratory sections to check their progress and on occasion to "kibitz" during the discussion. A uniform grading system has been set up. Each Taken from a paper presented before the Division of Chemical Education at the 148th National Meetine of the American Chemical Society in Chicaeo. Sentember. 1964 YOUNG; JAYA,, "Practice in ~ b i & i n ~ , '~;r e r k e e ~ a lInc., l, Englewood Cliffs. New Jersey, 1958.
student is graded by his instructor on each day's performance in the laboratory. He is also graded on his performance in the laboratory discussion period when it is his turn to make a class presentation. Each week a t the beginning of the discussion period each student submits a one-page resume of his current projects. Pairs of students are called on to make an oral presentation approximately every other week; both their r6sum6s and their oral presentations are graded. All r6sum6s are returned a t the end of the discussion period. Each student also submits a written report on each experiment on which he has completed any work. These are graded by the student's instructor and, after discussion with the student, are turned into the department for permanent filing. To supplement the student's laboratory and lecture texts, some 25-30 other general chemistry and higher level texts have been placed on reserve in the University library for the exclusive use by the students taking general chemistry. The students make extensive use of this reference shelf when they are reminded of its existence. Student reaction to the approach has been evaluated by questionnaire. More than t.wo-thirds of the students favor the approach. Perhaps surprising is the fact (also elicited from the questionnaire) that they prefer to carry on the give-and-take of the discussion period with their instructor present, but not one of the professors. The total professorial time spent directing the laboratories has not been appreciably more than was formerly spent directing the use of a more conventional text. Both weekly staff meetings and monitoring of graduate student classes have been customary a t the University of Detroit. As with any laboratory approach, more time is necessary at the beginning of the academic year. Contrary to expectations, the number of accidents in the laboratory has decreased since the open-end text was introduced. The greater diversity of chemicals and equipment in use seems to be more than offset by the fact that an experiment of a student's own invention is more familiar to him. I n view of the above experiences, it is the considered opinion of the staff a t the University of Detroit that a successful use of the open-end approach is possible with graduate assistants aslaboratory instructors.
Volume 42, Number 10, October 1965
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