J a m e s W. Barnes,I J o h n H. B e d e n b a u g h 2 and Fred W. Brown University of Southern Mississippi Hattiesburg 39401
The Use of "Programmed Lectures" in Freshman Chemistry
W e have experimented with a n unusual approach to teaching freshman chemistry that involves the use of "programmed lectures." This nontradi.tional approach offers four outstanding features in that i t (1) virtually insures constant attention by the students, (2) reinforces the learning of concepts that have been traditionally difficult for students to master, (3) enables the students to actively participate in the class by responding to questions, and (4) allows the instructor to evaluate student performance daily. Our schedule (which was not altered for this experiment) requires thirty-six weeks of instruction subdivided (for purposes of testing) into three-week "terms" with a test a t the end of each term. The experiment involved the introduction of "programmed lectures" a t intervals into the normal sequence of conventional lectures during four terms of the twelve-term school year. I n these four terms five general topics were taught by the experimental approach. The five topics: atomic structure, molecular structure, bonding, solutions, and equilibrium, were chosen because of the difficulty encountered by students studying . - these topics during the last five of the authors' teaching experience. The ''programmed lectures" were introduced by the following statements. 1) During this three weeks term you are to respond to questions and/or incomplete statements presented to you during the class period, and your responses will determine how well you understand the material presented to you by your instructor. You will have no tests, other than these questions, unt.il the regular test at the end of the three weeks term. 2) On your desk you will find an answer sheet that contains a blank space for the question number, followed by five numbers. These five numbers corrapond to multiple choice responses to questions or incomplete statements. 3) At irregular interval? during the lecture your instructor will flash a question or incomplete statement on the screen with the overhead projector. The time allowed to respond will depend upon the difficulty of the question. 4) The following statement is a good example of the type of material that your instmctor will present to you. (This is actually shown on the screen). Yon will have fifteen seconds to choose an answer. Select the correct. ending far the electron configmation of carbon in the ground state, which begins: 1sa2s2-
~PP
(3) %a (4) 4 ~ ' ( 5 ) 3s' (1) 38' ('4 5 ) You should wrlte the number of the question in the blank space, read the quest,ion or incomplete stat,ement carefully, select the option that you think is correct,, and then circle the corresponding number on the answer sheet. If you have ndditional time. cheek vour work. Whenvou are satisfied withvoor turn your answer sheet over.
After all students had selected an answer, a short period of time was devoted to a n explanation of why certain options were incorrect, and the correct option 622
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Journal of Chemical Education
was indicated. This explanation was deemed critical to the success of this teaching approach because it supplied a reinforcement factor for those who selected the correct option and permitted adjustments in understanding for those who selected an incorrect option. Throughout each lecture period the students were presented ten or more multiple choice questions or incomplete statements, each of which followed the presentation of a difficult concept. The questions were arranged in an irregular sequence so that the students could not anticipate when a question or questions would be presented by the instmctor. At the end of each class period the answer sheets were collected and the scores recorded for use as daily grades. I n general this teaching approach was well liked by the majority of the students and a significant number showed an increase in performance on regularly scheduled tests following the "programmed lectures." This significant difference was determined by comparing test scores on "programmed lecture" material with test scores obtained during the twenty-four weeks of traditional lectures. The most obvious outcome of the experiment was the attention given to the lectures during the twelve weeks when the "programmed lectures" were used and for a period of time after their use. Students were more likely to ask questions when the meaning of a concept was not clear. As further evidence of their interest, students were often noted comparing answers to questions asked during the "programmed lectures" after the class had ended. This involvement by the students during the class. period helped to make the "programmed lecture" a true learning session. It has been reported by bat tin^,^ Lambert,4 Smith: and Trahanovsky6 that unusual or nontraditional methods of teaching frequently result in better learning situations in the classrooms, but they are seldom used because of the time involved in preparation for classes of this nature. "Programmed lectures" are difficult to prepare and consume a considerable amount of the instructor's time prior to the class lectures. However, it should be noted that, once prepared, the "programmed lectures" can be used with future classes with a minimum amount of revision. Based on a paper presented before the Division of Chemical Education at the 20th ACS Southeast,ern Regional Meeting, Tallahassee, Florida, December, 1968. 1 Present Address: Chemistry Department, Pearl River College, Popla.rville, Mississippi, 39470. 8 To whom correspondence should be addressed at Department of Chemistry, University of Southern Mississippi. a BATTINO, R. B., J. CHEM.EDUC., 43, 281 (1966). 4 LAMBEET, F. L., J. CHEM.EDUC., 40, 173 (1963). 6 SMITH,R. B., J. CHEM.EDUC., 44, 148 (1967). 6 TTRAHANOVSKY, W. S., J. CHEM.EDUC., 45, 536 (1968).
