Homer A. Smith, Jr. Hampden-Sydney College Hampden-Sydney. Virginia 23943
The Evolution of a Self-paced Organic Chemistry Course
Although self-paced Keller plan chemistry courses (1-12) are rapidly increasing in popularity, many reports of them in the literature discuss only the initial offering. This is unfortunate because the instructor in a mature self-paced course, having recovered from his initial state of enthusiasm and effort, is in a better position to assess objectively the results of the course. In addition, experiences over a longer time span may serve as a more effective model for those planning to initiate a self-paced offering. The purpose of this article is to trace the evolution of our self-paced organic chemistry course over a three-year period hy outlining the reasons behind the important changes that were made and assessing their effects. Our course, one of relatively few self-paced organic courses reported (13, 1 4 ) , began as an orthodox Keller offering, as outlined in a previous paper (15). Taught by self-paced instruction since Septemher, 1972, this two semester course enrolls 30-45 studens, mostly preprofessionals and majors, drawn from a fairly homogeneous student body with SAT scores slightlv above average. No alternative lecture section has been offered. The assoc>ated laboratory is a separate, independent course. The textbooks (16-18) and mechanics of the course have remained essentially aspreviously described (15). We remain convinced that the principal determinant of success by a self-paced course is theavailability of a detailed study guide for each unit. The performance of our tutors. drawnin each case from the pre;ious year's class, has been uniformly good during all three years. They have been strict hut fair in grading unit tests, dependable in attendance, and committed to assisting their charges. The tutors for the 1973 and 1974 courses had themselves taken organic by self-paced instruction. As a result, they required very little training, and tutor-instructor meetings outside class durine the nroeress of the course were found & he largely superflno& ~utksYhave heen given one hour of credit per semester in Special Topics, an alternative easier to sustain than payment in times of budgetarv . . restraint. In a format of six class hours per week. we continue to find that a tutor should handle on& eight oi nine students if long waiting times are to be avoided durine periods of peak arti;4ts. In ahdition to supervising the tutors and assisting individual students. the instructor's classnx,m role has inciuded grading certain review units for every student, a function which has proven necessarv in order t o prnperly monitor thequalityof learning. In a classof thissize, the instrurtor ran easily grade l(loo of the units without adversely affecting his othe; functions. Student procrastination, often reported as a major problem in self-paced courses, has not proven serious in this course. Table 1shows an excellent record of unit completion each semester with only a minimal percentage of d;ops. We attribute this performance to two factors: (1) the high motivation of students competing for admission to graduate and professional schools, and (2) the credibility that mastery of the material will lead to passine the unit test (and that failure to do so will not), hrougk aho& by thorough accord between unit performance objectives and test questions. Procrastination has Seen most severe a t the beginning of the second semester segment each vear. a o ~ a r e n t l vreflectine the students' assessment that Lother arhlloui jiurney lies ;head but indicatingself-ronfidence that thev ran maktt the trio ranidlv . once the; have rested from the one just comp(lete2. By the
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510 / Journal of Chemical Education
Table 1.
Record of Unit Completion Percentage
of students'J Semester
completing all units
Fall. 1972-3 Spring. 1972-3 Fall, 1973-4 Spring. 1973-4 Fall. 1974-5 soring. 1974-5 Including students who received
Average percentage of units completedb
..
Percentage drops
"
W grader (withdrew, parsing).
' b Excluding rtudentr who received W grider.
middle of second semester each year, class progress has returned to normal, and the record of unit completion is in good accord for first and second semester segments (see Table 1). We continue to require that a student move through the units in sequential order during the first semester. At the beginning of the second semester the student also proceeds sequentially, continuing from the last unit he compieted the previous semester. This arrangement is simple and effective but would require close cooperation if the second semester segment were taught by a different instructor. After the first year, the maximum number of units each semester was increased from 20 to 21. The 37th unit completes the basic core of organic chemistry, after which the student need not nroeeed ~~~-~~ sequentially and may choose among various units on special topics in nrder to complete the maximum of 42 units for the year. The nonsequential units have covered the following topica, in decreasing order of popularity: protein biosynthesis; common biological molecules; nucleic acids; collateral reading; departmental seminars; heterocyclics; polysaccharides and natural products; reduction; uv and mass spectroscopy; spectroscopy problems; pericyclic reactions; and advanced SEAr reactions. Credit for the collateral reading unit is earned by reading 500 pages or more from a list of a~proximatelv200 books on such subjects as history and philosophy of sc$nce and medicine. More than half the class has elected this unit. readmg in fields they would probably not otherwise encounter in college, thereby receiving a worthwhile contrihution to their liberal education. Credit for the seminars unit is earned hy attending five depqrtmental seminars. This unit, now elected by almost half the class, serves to populate our seminars, aids in recruiting majors, and helps motivate students by frequently illustrating the application of principles covered in elementary courses. The seminars unit seems to he a more successful approach than entertainment lectures. In the firstyear of operation, semester grades were determined solely by the numher of units comnleted. As indicated in Table 2, a large proportion of the class attained high grades. In the opinion of both students and instructor. most enrollees worked harder than in a conventional course. However, it soon became evident to the instructor that some of the less able students were obtaining high grades without really mastering some important conrepts. They were passine unit tests onlv after several attempti, more by sheer effort than by clear understanding. T o ameliorate this problem, the course materials fur the second year were revisid to contain seven review units rather than four, and important concepts such as reso-
.~
Table 2. Percentage Grade Distribution for 1973
Grade
Spring Semester
1974
1975
nated. The overall result was essentially no change in class grade point average k-. o a ).. ~&assessment'of the course a t the end of two years was as follows. (1) Class attainment was good in the opinion of stndents and instructor but average as measured by exam. By either standard, the grade distribution was too skew. (2) The class needed to be better prepared for an exam situation. Whatever the imperfections of exams, most students will have to exhibit their knowledge of organic chemistry in exam situations in later courses, on achievement tests. etc. (3) The less able students were working very hard and achieving better than they would in a conventional course. The more able students were achieving competence but were not being pushed toward excellence. One change which might treat some of these problems would be to add more topics and require more units for a given eutde. Such a chanee was considered unwise because the student completing 22 units was already covering a 1 1 2 the basic material and several of the soecial tonics chaoters from a long and rigorous text. Also, we'had no iesire to make the course an endurance contest.. reolacine the nossihilitv of pacing oneself with the necessity for u&e&i&ing effort. A better alternative would be to use "honors" units (6, 20), completion of which would count toward earning a high semester grade. Such units might contain difficult review topics or enrichment material, or both, but could be omitted from the sequence a t the student's option. We believe such an aoproachis attractive although we doubt that it would improve exam performance substantially. Another change would be to make the unit tests more difficult. Such a change was rejected for several reasons. First, the existing tests were considered thorough and difficult and already posed a substantial challenge to most students. In general, these tests were harder than those given previously in lecture classes and required application of principles, combinations of concepts, and logical extensions. Making the tests "trickier" would place a premium on intelligence apart from learning. Either harder or "trickier" tests would discredit the students' belief that effective learning leads to success on units, seriously reducing the motivation to proceed through the units, and causing loss of most of the virtues of self-pacing. The less able students, who were already essentially overachievers in the course, would find themselves able to proceed slowly or not a t all repardless of. effort, .. . and would end UD dropping or a t best completing fewer units without learning them any better. ~ a t h ethan i rationalize away the exam performance of the class, we resolved to prepare them better for exams within a self-paced format. addition, the use of exams offered a needed means to distinguish between competence and excellence. In many self-paced comes, the student is guaranteed a certain grade based upon units completed, typically "B" for completion of all units. The grade can be raised but not lowered by the final exam. This policy is quite unsatisfactory because the many students who typically elect to forego the exam lose the values of the testing experience, the review of the material, and the synthesis of concepts. Those who take the exam, whether by choice or requirement, often do so with inadequate preparation owing to their perception that they might win but cannot lose (6, 14,19). On the other hand, a policy by which the exam is the major or sole grade determinant would greatly decrease motivation to complete all the units.
.
.
1
X)405060X)8090103 EXAM AVERXE. % Grading surface fadetermination of semester grede.
nance and stereochemistry were reiterated by frequent use in ohiectives of units followinz their inuoduction. The reiteration and review were quite heneficial to less able students, whose performance on later review units was much improved. The more able students proceeded rapidly through review material hut appeared to do so without gaining much new knowledge. Two-Year Assessment
At the end of the second year, a required final exam was administered to obtain an assessment of class attainment. The ACS standardized organic exams were judged to be unsuitable for this purpose because of their strong bias toward the functional group approach used by certain other textbooks. A locally prepared exam was used, about half of which consisted of a set of multiple choice auestions which had been administered three before rb the instructor's lecture class using- the same textbook. There was no statistical difference between the two classes' averages on the common part of the twoexams, a result similar to that rewrred hvorhers (3, 5, 6, 19). However, the self-paced class distribution had significantly fewer low mades but also fewer high ones. It has heen argued that the difference in atmospheL and format hetween self-paced unit tests and a sinale final exam is vreiudicial to a sklf-paced class and that
