John N. Vournakis'
Massachusetts Institute of Technology Cambridge, 02139
A Noncompetitive Introductory Organic Chemistry Course for Premedical Students
Introductory organic chemistry occupies a special niche in the premedical curriculum of most colleges and universities. Students often regard the organic chem course as the "make or break" test, equating success with a high probability of being accepted for admission by a medical school. Organic chemistry teachers are forced to face the spectacle of hundreds of competitive premeds slugging it out for good grades. The present rush for admission to the medical and para-medical professional schools has compounded the pressures on serious students. These and corollary observations prompted me to investigate the possibilities of creating a new system for teaching organic chemistry. I intended that this new system meet two primary objectives: (1) That it remove student-student competition and replace it with student-content involvement; i.e., that it focus the student's attention on learning the content of organic chemistry without the fear of having to fall somewhere high on a grading curue, and (2) That it improve the level of understanding of organic chemistry principles compared to that achieved by using the normal system of instruction. The teaching method developed and some results using it are described in this article. Introductory Organic Chemistry at MIT Approximately 60&700 students enroll in Chemistry 5.41, Introduction to Structure, Bonding and Mechanism (introductory organic chemistry), a t MIT annually. In recent years the percentage of premedical students in this course has been rising rapidly. Currently, approximately 65-70% of the chemistrv 5.41 students intend to seek admission to medical schbol. Students from all four undermaduate classes register for the course. Freshmen and sophomores are in largest numbers by an order of m a g n tude. An increasing number of graduate students, particularly physicists in the process of retraining for medical school, have been enrolling since 1970. Chemistry 5.41 has been taught in the traditional three lecture per week format since its inception. Recitation sections are also scheduled for students. Two or three one hour exams plus a final exam determine the students' grades. Lectures are held in a large auditorium that is able to accommodate the entire class (all 600-700 students) a t one time. The intellectual scope of Chemistrv 5.41 is contained in two unpublished textbooks written by Professor Dan Kemp of MIT. These hooks do not cover the wide range of material given cursory treatment in many organic chemistry textbooks. Rather, they focus on a specific task: to provide the necessary background in general chemical concepts, organic chemistry principles, and logic to enable students to understand the reactions and reaction mechanisms of the carbonyl functional group. The hooks do not deal extensively with nomenclature, nor with the chemistry of other functional groups. Kemp's approach is unique in that a theoretical basis is established and immediately 'present address: D~~~~~~~~~ B ~ Lyman ~ Hall,~ S y r a ~ cuse University, Syracuse, New York 13210. B. ZKeller,F. S., J. Appl. Behnuior Anal., 1, 19 (1968); creen, A,, Amer. J Phys., 39, 764 (1971); White, J. M., Close, J. S., and McAllister, J . W., J. CHEM. EDUC., 49,772 (1972). 742
/ Journal ot Chemical Education
applied to a specific case. Students discover the reasoning process involved in modern organic chemistry research. Chemistry 5.41 does not include laboratory work. Organic chem lab is a separate course at MIT. Self-Paced Chem. 5.41 The revised method developed for teaching Chem. 5.41 at MIT is a modification of the Keller Plan of Personalized I n s t r ~ c t i o n .The ~ new course is referred to as SelfPaced Chem. 5.41. The content of Chem. 5.41 is suhdivided into 12 Study Units. Each study unit includes a Study Guide and a Unit Quiz. The course has a Final Exam and a Molecule Study as its only other major components. Students are required to do the assigned reading and problems given in the study guide, pass each of the 12 unit quizzes, turn in one molecule study, and take the final exam in order to pass the course. All this must be accomplished in one semester. They are free to move at their own pace within that time limit, i.e., they can complete the course in one month or even one week if so motivated. The course is taught by an instructor and several student tutors. A ratio of one teacher (includes tutors) per 20 students is maintained. The course operates out of a central office manned by the instructor and tutors. Students come to this room for personal help with problems related to the content of the-course. Unit quizzes are administered from this office as well. Schedules are arranged so that the course central office is open to students more than 30 hours per week. Students can make specific appointments with the instructor if they need special help that tutors are unable to provide. A room adjacent to the central office was converted into a mini-library and study area for the course. All pertinent reference materials, molecular models, film loops, and other supplementary materials are available in this room during tutorial hours. One additional neighboring small room is used as a quiet area for quiz taking. Students work their way through Self-Paced Chem. 5.41 by passing each unit quiz, starting with quiz 1 and sequentially through the 12 quizzes. They are given the complete set of study guides at the beginning of the semester. They are required to submit one molecule study (see below) and to take a two hour, comprehensive, final exam following completion of the unit quizzes. Students are graded A, B, F, or I (incomplete) as follows: A's are given to those who complete all quizzes, turn in an acceptable molecule study, and score 85% or above on the final; B's to those who complete all work but score below 85% on the final; F's or I's as appropriate to those who do not complete all work. Study Guides and Quizzes A separate study guide was prepared for each unit of Self-Paced 5.41. Study guides begin by stating the ohjectives of the unit in fairly general terms. Specific reading and problem assignments (from the two Kemp textbooks) are Supplementary reading suggestions are made ~ given. , available in the course reading room. Supplementary readings are chosen to repeat and enhance the course material. The study units tend to focus on one major chemical
principle. The list of the titles of the study guides for the 12 units, shown in Table 1, indicates the scope of topics covered in the course. The study guide titles reflect the sequence of topics found in the textbooks. The unit quizzes are designed to test the student's understanding of the central chemical concepts presented in the particular unit. Quizzes are administered by the teachers on duty in the central office. Students are allowed to use hooks or other reference materials during the quiz, i.e., the quizzes are "open-hook." Each quiz consists of two questions. They are designed to require approximately 30 minutes of time for completion, hut students are allowed u p to 2 hours. Grading Quizzes Quizzes are graded, by the teachers on duty, immediately following completion by and in the presence of the student. Quizzes are graded pass or fail. A pass is awarded when the student demonstrates the ability to answer everything on the quiz correctly. This is established by the grader (instructor or student tutor) either from the quiz paper directly or by asking the student questions during the grading. The personal contact aspect of this quiz grading procedure has several unique advantages. It allows students who made trivial errors to demonstrate their understanding to the grader and to receive full credit. Students who do not fully understand the material are discovered and can be given appropriate direction and help. Students receive immediate feed-hack on their progress while the . . material is fresh in mind. A pass on a quiz gives the student the green light to proceed to the next unit. A fail requires that the student take a second quiz on the same unit a t a later date. The Molecule Study The .molecule study is a kind of game that has the following format. The instructor provides each student with the molecular structure of an "unknown" organic compound. The student must prepare a report that answers the following questions What is the scientific name of the compound? Where is it found in nature? Who discovered it? When? How? How was the molecular structure determined? By whom? When? What are the major reactions of the molecule? Haw can it be synthesized? The report should he as brief as possible, hut must he neatly presented and must include a complete bihliography documenting all findings. The molecule study assignments are made a t the beginning of the semester. They must he completed before a student can receive a passing grade in the course. Student Tutor Selection Students selected to he tutors in Self-Paced 5.41 are all undergraduates who have demonstrated to the instructor sufficient expertise in organic chemistry. They are required to pass all unit quizzes and the final exam to A grade level. They are interviewed by the instructor to determine their ability t o discuss clearly the concepts in the course. Judgements are made regarding the ability of the potential tutor to interact and relate well with the SelfPaced 5.41 students. Most tutors selected have been chemistry majors with two or more advanced organic chemistry courses on their record. They are all paid, on an hourly basis. Selection of Students Students who enroll in Chem 5.41 are free to opt for either the lecture-recitation or self-paced format. Limitations are placed on the numher of students allowed into the self-paced section, so that a lottery system is used to
Table 1. Title of Studv Guides Unit number
Title of study guide
4
Thermochemistry Aeid-Base Chemistry PredicLing Aeid-Base Reactions Nueleophilic Displacement Mechanisms Nucleophiles and Leaving Groups The Csrbonyl Group Grignsrd Reagent. and Reactions Csrbanyl Chemistry Revisited: Enoliration. Tautomerism. Mechanisms and Reaction schemes The Carhohvdrste Game
5
6 7
8 9 10 11
Table 2. Student Enrollment and Performance in Self-Paced 5.41 Between 1970-73 Number -king admission to self-paced
Year
5.41
Fall. 1970 Spling, 1971
47
Fall, 1971 Spring. 1972 Fall. 1972 Spring, 1973
Number allowed into self-paced
63 144 119
loob 70'
5.41
%A
20 20 80 60
50 40 36 38 54 75
19'
S1
Grades %B %F 40 40
53 48 42
25
%I
5 5 4 5 4 0
5
15 7 9 0
0
'This indudes a large number of students who sought to be part of a 5.41 offered to 40 students during the January
~ m s hsession of Self-Paced
IAP (Independent Activities Period) at MIT. T b M1T C h m . Dept. had discontinued offering the self-paced option. These numbers are approximate, as careful records were no longer taken. 'These numbers include students given special permission to do 5.41 selfpaced for a wide variety of reasons.
Table 3. Petformanee of Students in Self-Paced 5.41 by Class Between 1970-73 Class
Total number enrolled (1970-73)
Fmhman Sophomore Junior Senior Graduate ~otal
104(50%) 48(23%) 32(15%) 6(3%) 1718%) 207(100%)
%A 29 35 41 67 46
...
Grades %B %F 57
48 53 33 52
...
%I
4 9 3 0 2
10 8 3 0 0
... . . .
choose the students when the recluests exceed the numher of openings. No attempts have been made to select for a snecial "tvoe" of student. MIT students are quite familiar d i t h self-paced courses and, therefore, are capable of making an informed choice. Development and Trials Self-Paced 5.41 was developed and tested in three stages. The initial versions of the study guides and quizzes were prepared during the Spring of 1970. Six undergraduates were paid to act as trial students during the initial testing. Their performance and comments were used in the preparation of an improved, second version of the course. This was made available to 20 students each semester during the 1970-71 academic year. A final major revision of the course was undertaken during the summer of 1971. These materials were used during the 1971-72 and 1972-73 academic years. A total of 150 students passed through Self-Paced 5.41 during that time. Results A laree amount of information rezardinz the enrollment and pezormance of students in ~ e l i - p a c e d5.41 is summarized in Tables 2 and 3. Grade distributions for the various trial periods and as a function of student classes are shown. Final exams were modeled after those given to the lecture-recitation students. The detailed structure of the Self-Paced 5.41 final exam was identical to the lecturerecitation final; i.e., the number of short answer questions, multiple choice questions, quantitative problems, reaction mechanisms, syntheses, etc., was the same. The actual questions were as close to being identical as possiVolume51, Number 11. November 1974
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ble, e.g., numerical changes were substituted in quantitative problems, similar syntheses were asked for, and the same chemical concepts were tested for. I t was not possible to give exactly the same final exam due to timing nroblems: the self-naced students would take their final at bdd times during the semester. It was clear that Self-Paced 5.41 students performed significantly better on the final exam than others, since between 38-75% (Table 2) scored better than 85% and achieved A grades. Although exact data is not available, no more than 20% of the lecture-recitation students were able to do as well in any of the test periods. These results, though impressive, must be tempered somewhat, given that the final exams were not the same in the two test groups. It is hard to speculate on how the differences in the final exam might have affected the comparison between the two groups. The self-paced finals were given to the head instructor of the lecture-recitation section for comment and criticism. Feedback never came. A more enthusiastic and coordinated development effort would include certain controls, e.g., giving both self-paced and lecture-recitation groups identical exams at various stages during the semester. The particular situation a t MIT made such obvious experiments impossible. However, the results do stand as significant, if not fully developed. Student Remarks
A poll of student opinion was taken a t the end of each semester. Responses ran generally in favor of the selfpaced format. Selected examples of comments from students follow I feel the main advantage of Self-Paced 5.41 is that when a student finally passed a unit, he had to understand it to the mader's satisfaction. There was no class average tvne -. of mading, thereby eliminating the situation where the majority of the students could pass an exam without understanding what they were doing. In the self-paced version of 5.41 the student has to explain to the T.A. what happens and why. This is really goad. The main advantage of the course was the self-paced set-up which allowed students the chance at completing the course at their ownrate. The course was good except that it suffers from not having many lectures. A lecture adds a great deal to the written material. However, it was fun to go in and talk to the T.A.'s about the material I was studying at s particular time. You had to struggle with the book at times, but you had to understand the material well to take the quizzes and convince the people you knew your stuff. The course had t w much extra hull. The molecule study seemed to me to he a waste of time. It was easy to fall behind because no one made you do something by a certain time.
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'Were the Objectives Met?
The competitive pressures generally experienced by organic chem students were essentially absent in Self-Paced 5.41. Students had ample time to complete their work. The format was nersonal and informal. This eliminated much misunderst'anding between students and teachers. The "luck factor" was minimized. Students realized that only a clear understanding of the principles could and would allow them to do well. They knew that a fair reward (grade) would be given for achieving a sound understanding. They also were allowed a second and third chance without penalty. Students were totally unaware of and uninterested in the performance of their colleagues. They understood exactly the details of the task and set about i t with determination. The higher final exam mades amone Self-Paced 5.41 students compared to the lecture-recitation group indicated that the method seems to i m ~ r o v estudents' comprehension and retention of the course material. perhaps-the most significant feature of the self-paced course that led to its apparent success is the format itself, and not the details. Students had lots of opportunity for individual contact with teachers in a non-threatening environment. Students were encouraged to ask so-called " d u m b questions, and were often asked to demonstrate certain skills (e.g., ability to use logarithms, facility with definitions, etc.). The study guides, quizzes, etc., were merely accoutrements dressing the central feature of the course: close and honest contact between student and teacher. It became im~ossihlefor students to survive unless thev could answer the teachers clearly and with full understanding. Thus, much of the exam taking trickerv. professor second guessing, and peer competitionthat students engage in, in most large organic chemistry courses, was eliminated. Conclusions
The modification of the Keller Plan described above can be adapted for use with introductory science courses in many fields. The course should be one where a welldefined set of material is covered, preferably from a central textbook. Adequate time for development and testing should be allowed. Coo~erationamone teachers involved in carrying on the tradkional versions"of the course, and those involved in develodne the self-paced one is critical. Decision procedures in' r e b d to the criteria for and mechanism of introduction of the self-paced course into the ongoing curriculum should be established a t the departmental level a t the outset of the development. Instructional expenses for such a course are comparable to those encountered using the lecture-recitation style. The experience with Chem. 5.41 a t MIT indicated that serious-minded pregrad school and premed students welcomed the absence of severe competition, and the time freedom resulting from self-pacing.
