1. B. Rodewald,
G. H. Culp, and J. J. Lagowski The University of Texas Austin, 78712
The Use of Computers in Organic Chemistry Instruction
M a n y of the problems associated with teaching chemistry to relatively large classes of students arise because the techniques associated with the usual student-teacher interactions that are so successful for a small number of students, for numerous reasons, cannot he directly applied to the larger group. Often the financial problems associated with providing su5cient space, qualified instructors, and facilities to obtain the desirable pedagogical features of a small class environment with a large number of students are insurmountable. Under circumstances where lecture sections are large, tutorial assistance is minimized, recitation sections are handled by inexperienced instructors, and drill and practice become homework graded by nndergraduate assistants. The student has become more and more passive in his education. Computer techniques can he used to make the student an active participant by individualizing the instructional process. For a detailed discussion of the ways in which computers can alleviate some of the logistic problems associated with student numbers, facilities, availability of qualified instructors, time, etc., see the preceding paper.' We present here the results of a pilot study in which computer techniques were used to supplement an organic course. A Description of t h e Study From a first semester organic chemistry class, composed of 97 students who were either chemistry or chemical engineering majors, two groups of 40 students were selected a t random. The control group participated only in the conventional activities of the class (i.e., three lectures per week and the availability of the instructor on an individual basis a t his office hours). The experimental group, in addition to the conventional activities, had their work supplemented with specific programmed course modules that were correlated with the class lecture presentations. The programs were written for the IBM 1500 system. Instructional material is presented on cathode-ray tube or on animage projector. Student responses are entered on a typewriter keyboard. A picture of the terminal appears in the preceding paper.' The fundamental design of the instructional modules used in this project is tutorial or drill and practice incorporated in Socratic dialogue. A total of 9 modules were developed (Table 1). Each modular topic requires approximately 4&50 min of student time. The programs also include 63 colored filmstrip frames (16 mm) that are programmed as integral components of modules 1 through 7. The use of an image projector 1 CASTLEBERRY, S., 47, 91 (1970).
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LAGOWSKI, J. J., J. CHEM.EDUC.,
Journal of Chemical Educotion
under direct computer control often obviated the need to create complex displays on the cathode-ray tube as well as incorporating the advantage of color presentation. No limit was placed upon the number of times a student could interact with a given module. It was Table 1. -
A Description of the Study Modules Used in the Organic Chemistry Project
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1. The stmcture and geometry of alkanes
Tutorial; development of the concepts of covalent bonding and orbital hybridiastion and their utilization in predictine molecular structure and geometry. 2. Skeletal isomerism of alkanes Dri!l and practice, with provis~onsfor tutonal ass~stanoe; and stereochemmtry of cycloalkanes provides numerous examples for aid in the recognition of isomers; gives prGtice in the interpretion of the several types of structural formulas. 3. Nomenclaturealkanes and Drill and practioe, with provicycloalkenes mans for tutor~alassistance; concerned partly with common and, more extensivelv. with IUPAC nomenclatiie. Drill and practice; much 4. Preparations of alkanes greater than normal comelatlon with text: identifica tion of the reagents and conditions of specific reactions that may he utilized in the oreoaration of alkanes. 5. The chlorination of ethane: Tutorial; development of the use of thermodynamics in mechanism evalust,ine the ~ossible mechanis& pachways for the chlorination of alkanes. 6. The halogenation of alkanes: Tutorial; development of the use of thermodynamics in predicting the relative reactivitles of the halogens and of the substrate in free radical halogenations of dkrtnes; concurrent development of the concept of relative alkyl radical stshilities. Tutorial development of the 7. Stereochemistry f u n d a mentals recoerktion, identification. -~~~ a n d k i n i t i o n of enantio-' mers, diastereomers, and meso compounds. Tutorial, drill and practice; 8. General syntheses: twenty-one multi-step synA. Alkene releted syntheses thetie conversions are proB. Electrophilic aromatic vided, progressing from the substitution related simple to the more comsyntheses plex, The student provides ;.~r*p.bv+rrp procedure for eNcrring' the irwmr>ion; diicusci.m is ornvidcd. in r o far a~ispo&ble, on ' strength or weakness of each step in several of the convemons. A
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Table 2. Mean& Scores on Examinations and Quizzes suggested, however, that students work with a module only after the related material had been discussed in Mean lecture or had been read in the text used in the c o ~ r s e . ~ Mean Mean score of of differThus, the modules were utilized only as a supplement Source of control CAI ence to the conventional instructional method. Module evaluation group (%) . . group Evaluation of the programs was based upon (1) 1. Structure and geom- Quiz I 76.4 79.0 2.6 individual student attitudes using a subjective scale etry for various factors and (2) student performance on 2. Skeletal isomerism Quiz I1 69.1 79.0 9.9 HourExam 82.0 87.6 5.6 announced 10-min quizzes, hour examinations, and the T final examination. The quizzes contained items that 3. Nomenclature Hour Exam 72.0 89.6 17.6 I1 were specifically chosen for the purpose of evaluating 4. Pre~arationsof Quiz 111 48.2 59.2 11.0 modules. The hour exams were written by the instrucaikanes tor without regard to the content of the modules. 5. Chlorination mech- Hour Exam 75.3 88.4 13.1 anism I Thus, the hour examinations and final examination 80.1 0.1 Final Exam 80.0 contained items that were related to the modules as Hour Exam 56.3 80.3 24.0 6. Halogenation of well as some that were not, the scores on the latter alkanes I 5.6 61.9 67.5 7. Stereoohemistry Quiz I V serving as an internal reference for both the control 53.6 8.2 Hour Exam 45.4 fundamentals group and the experimental group. I1 FinalExam 62.5 67.1 4.6 A comparison of the mean score performances beH: Exam 69.5 83.4 13.9 8. General syntheses tween the control and experimental groups for CAIILl related and CAI-unrelated questions was performed 56.2 15.0 Final Exam 41.2 69.7 15.6 Final Exam 54.1 using the standard statistical ttest technique. The level of significancewas set a t 0.05 as a basis for estabMean scores are given an the basis of 100 points. lishing an unequivocal difference between the two groups. In other words, the probability of obtaining Table 3. A Comparison of the Mean" Scores for Items on the observed difference by random sampling from popuExaminations Unrelated to the Material in the Modules lations in which there was no real difference between the groups is 5 chances in 100or less. Mean Mean Mean score It was assumed that the impact of computer techof of differniques on student performance was the only variable in Source of control CAI ence evaluation group group (70) this study, since the instructor was overtly aware of the contents of only modules 3 and 5 and the students were Questions unrelrtted Hour Exam I 62.2 63.8 1.6 to modules Hour Exam I1 32.4 37.1 4.7 chosen randomly. '
Results and Discussion
Of the 40 students originally in each of the experimental and control groups, 29 and 28 students, respectively, completed the semester. The remainder dropped the course for various academic and non-academic reasons. The mean scores of the two groups of students for those portions of the various quizzes and examinations that were related to the material in the modules appear in Table 2. The mean quiz scores of the experimental group were markedly higher than the control group for the material in modules 2 (skeletal isomerism of alkanes) and 4 (preparation of alkanes) ; the same striking results were observed in examination scores for the material in modules 3 (nomenclature of alkanes), 5 (mechanism of chlorination), 6 (halogenation of alkanes), and 8 (synthesis). Module 8 appeared to be particularly beneficial. No significant difference between the two groups was found for the modules covering structure and geometry (module 1) and stereochemistry (module 7). This result for the former was not particularly surprising because of the elemental nature of the material. The essentially similar performance of the two groups for module 7 may arise from the absence of three dimensional representations in the filmstrip associated with the module. Additional support for the positive influence computer techniques make on student performance appears 2 The text assigned for this course was MoRRrsoN AND BOYD, "Organic Chemistry," (2nd Ed.), Allyn and Bacon, Boston, 1966.
HourExamIII Final Exam Questions related to Final Exam modules a
64.5 42.7 52.6
66.5 44.0 65.3
2.0 1.3 12.7
Mean scores are given on the basis of 100 points,
in Table 3. No significant difference between the two groups was observed on either the three examinations or on the final examination for items which were not related to the material in the modules. However, a comparison of the final examination results for related items shows a significant increase in the mean score of the experimental group. An attitude response questionnaire was given to the experimental group on the. last class meeting of the semester in an attempt to elicite their (subjective) impressions of using computer techniques in teaching organic chemistry. The results, which appear in Table 4, indicate student enthusiasm for these methods. An analysis of preferences showed that the modules on general synthesis, stereochemistry, and nomenclature were the most popular. Generalized student comments on the use of computers as study aids were also solicited on the attitude response questionnaire. The following few excerpts from these comments reflect the general attitude prevailing. Stimulated study (not that I think machine stimuli are the best. but for lack of a human alternrttive. it's a zood substitute). It (especially in the later module;i) organired the marerial in a very dear, logical propressim; scmewhat of an ourline form. It provided for practice in the areas of importance. . ..it cut down the time I needed to study on my own. Volume 47, Number 2, February 1970
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Table 4.
coverage of certain subjects was not sufficiently extensive. I n a real sense, this type of complaint suggests that the students recognize that computer techniques are useful study aids. It is apparent from this preliminary study that individualized instruction using computer methods can be developed for certain subjects which require that students learn (or gain insight through thought and practice) rather than the instructor teach. The number of students that can avail themselves of such instructional modules is obviousIy limited by the numher of terminals; however, it should be recognized that a terminal need not be located in a chemistry building nor does the student need to fit into a rigid schedule. Computer techniques can be made to provide individualized instruction by competent "instructors" (for it is really a human instructor with whom the student interacts) a t the convenience of both. Our confidence in the efficiency of computer techniques can be summariaed in the response of one of the students
Results of the Attitude Response Questionnaire
Strongly aeree
1. I enjoyed participating in the program. 2. The time required was wellspent. 3. I found that computer techniques were a definite aid to learning. 4. I recommend that 15 d l students in or(58%) aanic chemistry be given the opportunity to participate in the pro,, 5. I recommend con-
Aeree
Disaeree
Strongly disamee
11 (42%)
0
0
6. 1f&ilar progr&s were available in other courses, I would participate if eiven the O D D O ~
It (CAI) gave me practice by asking questions rather than just
They offered a quick going through of the material hut if the material waa not known, the program could usually point out what mistakes were being made. A better understanding of principles; i t forces me to study; s pleaaant wsy of studying. It created an atmosphere that was focused on the learning of the individual personally.
The primary disadvantage which the students associated with the present modules was the fact that they did not cover all of the material in the course or that the
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reading material and hoping i t was heing lemned; developed confidence; pointed out areas needing further study; stressed major points.
Acknowledgments
The authors express their sincerest appreciation to Dr. L. 0. Morgan for his guidance and assistance during the course of this study; to Dr. J. C. Gilbert for his unlimited cooperation; and to the Laboratory of Computer-Assisted Instruction and the Research Center for the College Instruction of Science and Mathematics for providing the funds necessary to conduct this investigation.
Programs for Correcting Student Balanced Equations and for Generating Numerical Problem Parameters Two computer programs have been written to permit high speed data processing to he used in the correcting of student balanced equations and to generate randomized parameters for use in numerical problems. I n the first program, students are given descriptions of chemical reactions and are asked to provide bslsneed equations for them. Their answers are submitted on IBM cards and are then fed into the computer. The program reads the cards, pinpoints errors, prints out an analysis of each equation, and computes a grade. The grading system used in the program is very similar to one which might be used by a. human instructor, but i t is much more consistent from one student to another since it does not become more lenient or strict during the process of grading a. e r o m of student n a m e . The second program was written to implement a system of assigning numerical homework problems. Students are given problems of the usual types. However, each student is given a different set of numerical parameters. This keeps students from copying answers from one snother and gives each one some feeling that he has s. personalized assignment. For eeeh problem the computer is given a set of typical parameters and the range over which each can vary. The program then produces a set of random values in the prescribed range for each oarameter. The comouter is also nrovided with aleorithms to calculate the correct answers so that student answers can he checced. The author would he glad to provide listings of either of these programs to interested readers. u
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BENTLEY COLLEGE WALTHAM, M A ~ S A C H ~ ~02154 ETTS
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Journal of Chemical Education
Table 4.
Strongly agree 1. I enjoyed participa-
2. 3.
4.
5.
6.
Agree
15 (58%) 11 (42%) 9 (35%)
ting in the pmgmm. The time required was wellspent. I found that computer techniques were a definite aid to learning. I recommend that 15 d l students in or(58%) aanic chemistry be given the opportunity to participate in the oroeram. I reco&m&d con21 tinued development (81%) of the program in organic chemistry. If similar programs 14 were available in (54%) other conrses, I would participate if eiven the o ~ ~ o c
Disagree
Strongly disagree
1
0
(4%)
0
0
o
o
0
o
0
0
1
0
(4%)
They offered a quick going through of the material but if the material was not known, the promam could usually point out what mistakes were being made. A better understanding of principles; it forces me to study; s plensant wsy of studying. It created an atmosphere that was focused on the learning of the individual personally.
The primary disadvantage which the students associated with the present modules was the fact that they did not cover all of the material in the course or that the
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coverage of certain subjects was not sufficiently extensive. I n a real sense, this type of complaint suggests that the students recognize that computer techniques are useful study aids. It is apparent from this preliminary study that individualized instruction usinn com~utermethods can be developed for certain s u h j k s which require that students learn (or gain insight through thought and practice) rather than the instructor teach. The number of students that can avail themselves of such instructional modules is ohviousIy limited by the number of terminals; however, it should be recognized that a terminal need not be located in a chemistry building nor does the student need to fit into a rigid schedule. Computer techniques can be made to provide individualized instruction by competent "instructors" (for it is really a human instructor with whom the student interacts) a t the conveuieuce of both. Our confidence in the efficiency of computer techniques can be summariaed in the response of one of the students
Results of the Attitude Response Questionnaire
Journal of Chemical Education
It (CAI) gave me practice by asking questions rather than just
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reading material and hoping it was being lemned; developed confidence; pointed out areas needing further study; stressed major . ooints. .
Acknowledgmenb
The authors express their sincerest appreciation to D,.. L, 0, M~~~~~ for his guidance and assistance during the course of this study; to Dr. J. C. Gilbert for his unlimited cooDeration: and to the ~ ~of Comuuter-Assisted '~nstruction and the ~ e s e b c h center for the College Instruction of Science and Mathematics for providing the funds necessary to conduct this investigation.
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