A self-study, one-paced basic organic chemistry course

Arnon Shani and Amnon Singerman. Ben-Gurion University of the Negev, Beer-Sheva, Israel. Which is true for students and teachers? “The organic chemi...
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A Self-study, One-Paced Basic Organic Chemistry Course Arnon Shani and Amnon Singerman Ben-Gurion University of the Negev, Beer-Sheva, Israel

Which is true for students and teachers? "The organic chemistry course continues to he a traumatic experience for a large number of students" ( I ) or "Undergraduate organic chemistry education is in an excellent state of health" (2).Our own experience during the last ten years1 has shown that regular lectures were less effective than our approach for teachinr the basic course in organic chemistry to chemistry majors. The curriculum for the B. Sc. in Natural Sciences in Israeli universities usually covers three years, and the basic twosemester or three-trimester course in organic chemistry is delivered during the second year, after general chemistry and some inorganic and physical chemistry have been taught. Chemical engineering students in our university used to join our chemistry majors in all chemistry courses including the organic chemistry one. During the first five years both types of students listened to the typical frontal lecture, without any involvement on their parts, except for the odd questions. The organic chemistry course included 2 X 2 hr meetings a week, for 26-27 weeks. Exercises were given to the students, to he solved at home and then checked by an assistant under the guidance and instruction of the teacher. The failure rate at the the 1975 class ( 3 ) ,we were somewhat surprised to learn that almost all chemical engineering students were reluctant to participate in this "experiment," while the majority of chemistry majors took to the idea and prepared themselves accordingly. The latter did, however, express apprehension as to whether they could stand up to the heavy load of self study in English (see later). As a result, the class was divided into two groups, and since 1976 chemistry majors have studied separately under the new program, while chemical engineering students continued the regular course. This paper summarizes five years of teaching the new course (1976-1980) to the chemistry majors. Description of the Course Several articles described the self-study or self-paced ap-

of the material in the syllabus is more important (8). We realized the advantages of the self-study approach and thought that small working groups in the classroom under the instruction of teachers, would he a better method for teaching the course. Thus, we combined the self-study and the active involvement of the students in the learning process, for a self-study, one-paced course in organic c h e m i ~ t r y .The ~ method included a reading assignment at home prior to the meeting (usually 20 pp. for one meeting of 2 hr), based on homework which consists of reading" (3-4 hr) and solving 3-5 problems as a preparatory exercise (1-2 hr at home). We then

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Ben-Gurion University of the Negev was established officiallyin 1969, while chemistry majors started at the end of 1969. (Hence,we call it the 1970 class.) This type of course in organic chemistry was developed for medical students during the 1973-1974 school year by M. Gorodetsky, of our department. We found that the average Israeli student reads and learns 4-6 pages of textbook English per hour.

1 st.

Quizzes sem. 2nd sem.

Examlnat~ons 2nd s e m

1st sem.

Student grades in quizzes and final examinations during 1976-1980. N = number of students examined. F = number of students failed (passing grade is 56). A = average class grade. held a meeting for 2 hr which included 10-15 min of a short introduction and a summary of the topic to he covered. Following this, the class (10-20 students) was divided into 3-4 small working groups. (We were the two teachers in the class and the solution to prohlems were pre-written, so we "spoke the same language" in class.) In these subgroups, the students solved more advanced prohlems on the topic based on additional material which was covered previously. At the end of the lesson, in the final 5-10 min, the correct solutions were presented with further emphasis on hasic concepts and conclusions. The teachers helped and guided the students in the process, usually by leading questions and demonstrating (at first) the approach to problem solving. No extra homework was given after the meeting because of a shortage of time, although students were encouraged to solve those prohlems which they did not finish in the classroom. (During one meeting there were usually 4-6 prohlems, with 1-3 items in each, and the students usually did not complete them all.) Ahead of time, the students were given several chapters with all reading assignments and prohlems to solve, but they usually did not prepare themselves earlier than prior to the coming meeting. The written material for each lesson included objectives of the meeting, problems to solve in class, and a summary of concepts and leading words from the material covered. We chose the "non-classical approach" textbook by Hendrickson, Cram, and Hammond (9),even though it is a more difficult text, mainly because the functional group concept as a working tool is lost. I t is much more difficult for the students, at early stages, to grasp so many different reactions in one group, such as breaking and forming C-Y bonds (Y = halogen, 0, S, N, H, C), or Nucleophilic Substitution at UnVolume 59

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saturated Carbon, etc. We thought that understanding the basic ideas of chemical reactivity and reaction types would help students in further studies, where the overall view of oreanic chemistrv is more imnortant. We believed that the ye& and in the t k r d year. The first semester of the course was devoted mainlv to more general conce~ts(chanters 1-11). while the second one mainly to chemicai reactions (chapters 12-24, excluding 21,221. During the course, three quizzes were given (two in the first semester, one in the second one), as part of the study, in order to give both the students and teachers information on how effectively the material has been assimilated. These quizzes included mainly questions whose answers were of "correctincorrect" type, to draw structures, and to complete simple reactions. The final examinations of each semester contained "open-questions"-type problems, where students were asked to elaborate on mechanism. rationalize sets of results. to suggest synthetic pathways to chemicals and other problems which were based on understanding rather than memorizing" facts and figures. Both quizzes and examinations were openbook. There were no students who dropped out for academic reasons, auart from those who failed the first semester and were not &owed to continue to the second. A questionnaire was conducted at the end of the course, and students were asked to answer more than 20 questions ahout the course, the method of study, the textbook. the examinatons, and the grades and express their opinions about the course. Discussion We were aware of the fact that the number of students every year was not high. (It ranged from a low of 7-9 students to a high of 19-20.) We realized that the total number is not sufficientlv hieh for statistical treatment. In snite of this. hv In other words, albeit the average grade was not'too high:their knowledge and understanding were much imoroved. The helow-average student could pass the examina'tio? and acquired a reasonable level of knowledge. The made distribution the three quizzes and the finalkxamiGtions is demonstrated in the figure. The first and second quizzes alwavs showed two unequal groups in the class. The mijority did not pass, while the smaller group mastered the material and did well on the quiz. The situation changed to a more normal distribution in the third quiz. The examinations at the end of each semester showed almost typical distribution, with a small numher at each extreme, while the majority got the average grade of 60-70. We assume that the "reverse hell" picture a t the beginning of the course is attributed both to the completely different and unfamiliar form of study and the difficult preparative work a t home, and the type of questions: either they knew and understood the material, or thev did not. The be memorized. They also had to read and cover more pages and material during that semester. The results show that a t the final examinations, more students were in the grade bracket of 56-64 in the second semester than in the first one. Total numher of failures is well helow that of previous years: First Semester

Total no. Failures

224

81 13 (16%)

Second Semester Total no. 72 Failures 7 (9.7%)

Journal of Chemical Education

This achievement by itself was enough to justify the efforts we devoted to the new course. Comments made by the students on the questionnaire showed that the students preferred the self-study, one-paced approach rather than the classical frontal lecture. Among the many reasons for this, they mentioned that the fact that they had to he prepared for the meeting forced them to read the material and understand i t well. They figured out that it was inadvisable to come to class without adequate preparation at home. But more importantly, they said they learned how to study, they gained confidence in themselves, and they found that through discussion they understood the material better. The better students helped us to discuss the problems in the working groups with the poorer students. They learned how to attack problems, to think properly, how to express their thoughts more precisely, and they felt as if they were in a private lesson, enjoying personal tutoring. They emphasized that this method caused them to think, not to memorize facts-a criticism which is often leveled a t organic chemistry courses. They found that on occasion, during a regular lecture, they felt they understood the material hut later found that this was not the case. This situation did not occur in the new course, because they kept asking questions until they were sure they had fully understood. This method kept them active, involved, and thus prevented boredom during the lesson. Some complained that they had to spend more time on organic chemistry at the ex pense of other subjects. Others recommended combining this method with short lectures from time to time, on more difficult subjects, or in order to summarize a topic. They also recommended this method for other courses with a small numher of students. The problem is, they claimed, that it is almost impossible to study more than one or two courses of this tvve a t the same time. course. ?his gave us the chance to help the poorer students right from the start, thus preventing them from leaving or failing the course. The personal and direct contact helped them to feel free to describe their difficulties. This informal self-conscious about making errors. Conclusion T o summarize, we believe that self-study, one-pace approach is a good one, suitable for many other courses in chemistry and other subjects, provided that the classes are no bigger than 30-35 students. Two or three teachers can work with 6 6 working groups of 4-6 students in each, while soluof faculty, advanced graduate students can take part in such a course. We found these students very enthusiastic, active, and responsible. The effort required in such a course is substantial; however, we feel that in this case the means justify the most satisfying end. Literature Cited (11 Ann. C h m ondEng. New8,Sept 25th.19781ssue.p. 32. (2) Division of Chemical Education A.C.S. Report of Organic Subcnmmittee of the cur^ riculum Committee,Part 1I.J. CHIIM.EDUC.,53. 25 11976). (3) We followed Roberts, J.D.. andCaseriu,C. C., '"BasicPrinciples of Organic Chemistry.)‘ W. A. Benjamin, Inc.,New York, 1965. (4) Emerson.D.W., J. CHEM.EDUC.,52,228 (1975). (5) Harrison, E.A, and Hiirrisun, A. M., J . CHEM EDUC.. 52,654 (1975). (6) Smith. H.A., J. CHEM. E ~ ~ ~ . , 5 3 , 611976) 1 0 andreferencsscited therein. (7) Pno1e.T. M..J.CHEM.EDUC.,54.750 (1977). (8) Whee1er.D. M.S., and Wheeie~,M. M ,J.CHEM.EDUC.56.462 (1979). (9) Hendrickaon. J. B.. Cr8m.D. J.. and Hammond, G . S.,"OrgmicChemistry:3rdEd., McCraw~HiliBuokCo.,Ne~ Ymk, 1170.