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In the Classroom 1104 Journal of Chemical Education Vol. 76 No. 8 August 1999 JChemEd.chem.wisc.edu Teaching Introductory Organic Chemistry: A Problem-Solving and Collaborative-Learning Approach Lois M. Browne Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada Edward V. Blackburn Faculté Saint-Jean, University of Alberta, Edmonton, AB, T6C 4G9, Canada Over the past quarter century, chemistry departments, faculty, and students have been challenged to change their approach to the study of chemistry (1–3). The need for a laboratory-centered curriculum (4 ) in which critical, creative, and complex thinking skills are developed has been well articulated (5–8). During the past decade, the laboratory component of introductory organic chemistry courses has received justifi- able criticism. As Pickering remarked (9), It is the process of abstraction that is so badly ignored. Organic labs have degenerated into cooking.…What matters for [students] is not practice of the finger skills of organic chemistry, but practice in the style of think- ing of organic chemists. The introduction of unknowns in lab experiments, not only at the University of Alberta but at many other colleges and universities (10, 11), was in response to student and faculty condemnation of the cookbook approach to teaching the organic chemistry lab. In spite of this, course exit questionnaires have continued to demonstrate student dissatisfaction with the experience in introductory organic chemistry. Common complaints are that students perceive little correlation between laboratory and lecture components; and therefore they can- not see the relevance of the laboratory curriculum. During our attempt to address these concerns and to improve our students’ learning experience, we were made aware 1 of the way of learning espoused by Wilson (3, 12). We decided to investigate the possibility of adapting the methodology he developed for small classes to accommodate the 250+ student course sections at the University of Alberta. The results of this study are presented in this paper. Introductory organic chemistry at the University of Alberta is taught either in the freshman (CHEM 161/163) or sophomore (CHEM 261/263) year 2 of the student’s program (13). The course is available to all students during the two- semester Fall/Winter Session or during the intensive six-week Spring Session, 3 the language of instruction being English or French. 4 The Problem-Solving Thesis and Concept of Collaborative Learning Instructor and laboratory coordinator collaborated to create an integrated, lab-centered experience in which students were introduced to organic chemistry from a problem-solving perspective in an attempt to develop the problem-solving and practical skills that are fundamental to this experimental science. To foster the critical, creative, and complex thinking skills of our students, we decided to develop a collaborative learning environment (14–23) in which students solve experiment- based problems in groups. The hope was to develop study groups that would help and encourage students, new to uni- versity life, as they studied organic chemistry, and also allay the evident apprehension 5 of many of the students. Problem- solving groups of four to eight students were therefore formed 6 with the purpose of solving challenging, instructor- provided problems—problems not exercises (PNE) (3), which emphasize the experimental nature of chemistry—and to planning the problem-solving labs (PSL) (12). The Lecture Component Whenever possible, the course instructor presented topics from a practical problem-solving perspective. In an attempt to model the thought processes of the organic chemist, ex- perimental results were discussed, explanations proposed, and tests of hypotheses developed. This process was introduced, for example, through a study of the free radical halogenation reactions of alkanes. After a review of the experimental evidence, a mechanism was developed. This was followed by a discussion about how this mechanism might be tested and what pre- dictions might be made on the basis of the mechanism. This thought process model was developed further during the study of nucleophilic substitution and elimination reactions. As the course progressed, students were more and more able to actively participate in the thought process; there was a gradual development of critical and creative thinking. The instructor ensured correlation between lab and lecture by relating the problem to be solved in the lab to the current lecture material. For example, criteria of purity were discussed at the start of the course, thereby introducing students to the concepts of melting point, mixed melting point, boiling point, refractive index, thin-layer chromatography, and infrared spectroscopy before their first PSL. The first PSL presented the problem of assessing the purity of a solid unknown and then identifying it. The problem-solving nature of chemistry and the col- laborative learning process were reinforced through the PNEs. 7 Library skills were developed and emphasized as students were shown that chemists situate their own work in the continuity of scientific thought that has elaborated over the years. The first PNE, therefore, consisted of a literature search in which students made extensive use of Chemical Abstracts and Science Citation Index. Subsequent PNEs emphasized the experimental nature of chemistry and paralleled the methodol- ogy reported by Wilson (3). Experimental data were taken

Teaching Introductory Organic Chemistry: A Problem-Solving and Collaborative-Learning Approach

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Page 1: Teaching Introductory Organic Chemistry: A Problem-Solving and Collaborative-Learning Approach

In the Classroom

1104 Journal of Chemical Education • Vol. 76 No. 8 August 1999 • JChemEd.chem.wisc.edu

Teaching Introductory Organic Chemistry:A Problem-Solving and Collaborative-Learning Approach

Lois M. BrowneDepartment of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada

Edward V. BlackburnFaculté Saint-Jean, University of Alberta, Edmonton, AB, T6C 4G9, Canada

Over the past quarter century, chemistry departments,faculty, and students have been challenged to change theirapproach to the study of chemistry (1–3). The need for alaboratory-centered curriculum (4) in which critical, creative,and complex thinking skills are developed has been wellarticulated (5–8).

During the past decade, the laboratory component ofintroductory organic chemistry courses has received justifi-able criticism. As Pickering remarked (9),

It is the process of abstraction that is so badly ignored.Organic labs have degenerated into cooking.…Whatmatters for [students] is not practice of the finger skillsof organic chemistry, but practice in the style of think-ing of organic chemists.

The introduction of unknowns in lab experiments, not onlyat the University of Alberta but at many other colleges anduniversities (10, 11), was in response to student and facultycondemnation of the cookbook approach to teaching theorganic chemistry lab. In spite of this, course exit questionnaireshave continued to demonstrate student dissatisfaction withthe experience in introductory organic chemistry. Commoncomplaints are that students perceive little correlation betweenlaboratory and lecture components; and therefore they can-not see the relevance of the laboratory curriculum. Duringour attempt to address these concerns and to improve ourstudents’ learning experience, we were made aware1 of theway of learning espoused by Wilson (3, 12). We decided toinvestigate the possibility of adapting the methodology hedeveloped for small classes to accommodate the 250+ studentcourse sections at the University of Alberta. The results ofthis study are presented in this paper.

Introductory organic chemistry at the University ofAlberta is taught either in the freshman (CHEM 161/163)or sophomore (CHEM 261/263) year2 of the student’s program(13). The course is available to all students during the two-semester Fall/Winter Session or during the intensive six-weekSpring Session,3 the language of instruction being Englishor French.4

The Problem-Solving Thesis and Conceptof Collaborative Learning

Instructor and laboratory coordinator collaborated tocreate an integrated, lab-centered experience in which studentswere introduced to organic chemistry from a problem-solvingperspective in an attempt to develop the problem-solving andpractical skills that are fundamental to this experimental science.To foster the critical, creative, and complex thinking skills of

our students, we decided to develop a collaborative learningenvironment (14–23) in which students solve experiment-based problems in groups. The hope was to develop studygroups that would help and encourage students, new to uni-versity life, as they studied organic chemistry, and also allaythe evident apprehension5 of many of the students. Problem-solving groups of four to eight students were thereforeformed6 with the purpose of solving challenging, instructor-provided problems—problems not exercises (PNE) (3), whichemphasize the experimental nature of chemistry—and toplanning the problem-solving labs (PSL) (12).

The Lecture Component

Whenever possible, the course instructor presented topicsfrom a practical problem-solving perspective. In an attemptto model the thought processes of the organic chemist, ex-perimental results were discussed, explanations proposed, andtests of hypotheses developed. This process was introduced,for example, through a study of the free radical halogenationreactions of alkanes. After a review of the experimental evidence,a mechanism was developed. This was followed by a discussionabout how this mechanism might be tested and what pre-dictions might be made on the basis of the mechanism. Thisthought process model was developed further during thestudy of nucleophilic substitution and elimination reactions.As the course progressed, students were more and more ableto actively participate in the thought process; there was agradual development of critical and creative thinking.

The instructor ensured correlation between lab and lectureby relating the problem to be solved in the lab to the currentlecture material. For example, criteria of purity were discussedat the start of the course, thereby introducing students to theconcepts of melting point, mixed melting point, boilingpoint, refractive index, thin-layer chromatography, andinfrared spectroscopy before their first PSL. The first PSLpresented the problem of assessing the purity of a solidunknown and then identifying it.

The problem-solving nature of chemistry and the col-laborative learning process were reinforced through the PNEs.7

Library skills were developed and emphasized as studentswere shown that chemists situate their own work in thecontinuity of scientific thought that has elaborated over theyears. The first PNE, therefore, consisted of a literature searchin which students made extensive use of Chemical Abstracts andScience Citation Index. Subsequent PNEs emphasized theexperimental nature of chemistry and paralleled the methodol-ogy reported by Wilson (3). Experimental data were taken

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JChemEd.chem.wisc.edu • Vol. 76 No. 8 August 1999 • Journal of Chemical Education 1105

from the literature. Students were queried about techniquesused and were often required to postulate a mechanism.

The Lab ComponentThe greatest fundamental change resulting from our work

was in this component. At the University of Alberta, teachingassistants (TAs) under the supervision of the laboratorycoordinator teach approximately 50 scheduled lab sections perweek (maximum 22 students per class). Generally, the TAshave the responsibility to introduce the experiment, explainunderlying experimental concepts, teach techniques, monitorthe students’ progress, and evaluate their performance.

The large number of students involved imposed constraintson the adaptation of our laboratory course to a problem-solving curriculum. Students could not have free access tolabs; they needed to adhere to scheduled lab periods.8 How-ever, to implement the problem-solving curriculum, studentsneeded access to technical information, and this was providedprimarily through a custom-designed lab manual (24 ) andvideotaped demonstrations of techniques (25, 26 ).

The topics of the traditional “cookbook” laboratorycourse were maintained in the PSL course so that students’learning and performance in the problem-solving coursecould be compared with that of students in the traditionalcourse. The first semester experiments introduce the studentto basic organic chemistry technical manipulations (see Table1 for a summary). A practical problem is posed that requiresthe use of a specific technique to work out the solution. Forexample, rather than studying melting point measurements,recrystallization, and thin-layer chromatography as a focus,the student develops these techniques in order to solve thepractical problem of determining the purity of and purifyingand identifying an unknown solid. Each new PSL introducesa new technical skill while repeating the use of those learnedearlier.

To facilitate problem solving, the custom-designed studentlab manual used a guided-inquiry approach. Each PSL wasdivided into experimental tasks. A list of available chemicalsand apparatus was provided, along with pertinent factualinformation and “hints” to assist the student in developing anexperimental strategy to complete a specific experimental task.

A series of questions was included as a prelab assignment; thequestions “walk” the students through a possible solution tothe problem,9 thereby helping them understand what wasrequired in the experiment. At the beginning of each laboratoryclass, the TA gave a brief review of the day’s experimental task,demonstrating a possible approach to solving the experimentaltasks by “thinking aloud” in order to display the thoughtprocess for the student to mimic. The basic techniques weredescribed in the lab manual and the showing of in-house-produced videos (25, 26 ) of each technique as it was encoun-tered emphasized the correct manipulations. Following the TAreview and videos, the groups worked out their own plans ofaction. After TA approval of the plan, the groups separatedinto pairs of students and proceeded to implement the solutionto the problem. Students soon developed confidence in theirown problem-solving capabilities. This allowed a transitionfrom group planning and partner work to individual experi-mentation as the semester progressed.

Implementation

The problem-solving approach was used during foursuccessive academic sessions. After the completion of eachcourse sequence, the curriculum was reviewed and refined.

The new pedagogy was first implemented in SpringSession 1995, a class of 100+ freshman and sophomore students,and the lab-centered curriculum was an immediate success.However the PNEs were less well received. They were toonumerous (seven during a three-week period) and were foundto be very difficult. It was therefore decided to reduce theirnumber and remove some of the more taxing problems.

In Fall Session 1995, the course was taught to approxi-mately 250 freshman students. The problem-solving strategy wasagain a success, with a majority of students acknowledgingits effectiveness:

I really enjoy the problem-solving techniques used in thisclass. It makes concepts more clear and understandingeasier.

In the problem-solving labs, TAs need to be interactivein their instruction. Resources were therefore developed tohelp new TAs in leading interactive discussion sessions with

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1106 Journal of Chemical Education • Vol. 76 No. 8 August 1999 • JChemEd.chem.wisc.edu

their students. Four concurrent laboratory sessions wereaudiotaped. The student questions and style of speech wereanalyzed. A list of student questions was compiled for eachPSL and used to develop the script for an animated video-taped demonstration10 of effective interactive teaching.

All freshman organic chemistry students (~1000) tookthe problem-solving laboratory component in Fall Session1996. One-third of the TAs assigned to the course had notpreviously instructed introductory organic chemistry. Incontrast, the sophomore class was taught using the traditionallab methodology. Again the problem-solving course was verysuccessful. The improvement in student performance in theproblem-solving laboratory compared to the traditionallaboratory was assessed through the lab exam. Students in theproblem-solving course performed ~6% better on similar labexams. They were also more successful than their sophomorecompatriots in answering questions about how and why tocarry out a basic technique.

Evaluation

Students’ experience of both the problem-solving courseand the traditional course was surveyed through anonymouscourse-exit questionnaires. Statements were made and the stu-dents were asked to rate their agreement or disagreement withthe statement using the scale 5 = strongly agree to 1 = stronglydisagree. Student response to the statement “Overall, the labis a valuable part of the organic chemistry course” was con-sistently higher for the problem-solving lab course (3.8–4.1)than for the traditional lab course (3.2–3.5).

An attempt was made to determine specific aspects ofthe lab program that influenced the students’ perception ofthe course. Generally students were aware of the importanceof technical skills and evaluated videotaped demonstrationsfavorably. As previously mentioned, students frequently arefrustrated because they do not understand the correlationbetween the lecture and the practical chemistry that they carryout in the laboratory. However, students involved in theproblem-solving approach to organic chemistry grasped theinterrelationship of lecture and lab, especially during theSpring Session when the course sequence is learned in aconcentrated time period.

Some students questioned the value of collaborativelearning for the PSLs and PNEs in the Fall Session, possiblybecause group members did not have well-defined tasks. Asa result, not all members of the group contributed equally.In contrast, students perceived that they learn more readilyand embrace problem solving more readily when workingwith partners. In the Spring Session the groups are more co-hesive and the intensity of learning is far greater. The smallerstudent numbers (100–120) during the spring allow studentsto choose their groups, a process that is impossible in thefall. Klemm has reported (14 ) that “students need to believethat they are linked with others in a way that ensures that theyall succeed together. Each participant may have a differentrole, but that role must be crucial to the group process.” Theimportance of group participation and the role of each memberwill be emphasized as we further refine this pedagogicalapproach to learning.

An objective of the problem-solving lab course is to buildstudent confidence and independence in experimental work.

To evaluate this, students were asked to give their impression ofthe first term problem-solving laboratory course. The surveyshowed that students learning laboratory skills in organicchemistry using the problem-solving approach have a strongerbelief in their capabilities to carry out basic practical chemistry;they also are more confident about their knowledge andunderstanding of the underlying concepts than students learn-ing laboratory skills using the traditional, recipe-style approach.

Student demands on TAs changed as a result of the newapproach. The TA instruction became focused on helpingstudents to be successful through hints, rather than step-by-step explanations. Most TAs agree with the course format andbelieve that this approach benefits student learning, as re-flected in the following comment:

I enjoyed teaching the problem-solving labs in the firstterm. The difference between this course and the tradi-tional one could be noticed right away. Here, studentsare given all the tools to do the experiment instead ofsimply the written procedure. They are required to think,understand all principles, then experiment and makedecisions (with minimal assistance from the TA). Becauseit is more challenging for them than to blindly followthe procedure, they get involved much more and theydo enjoy it a lot more. All experiments seem to be morerewarding for students later when they worked on theirown. Students question each step they need to do, so theydevelop much more understanding of what’s going on.The techniques and the basics of organic chemistry thatthey learn, they remember longer and know how toapply them in following experimental organic chemistrycourses. This was obvious at the beginning of the sec-ond semester course, when the class was a mixture ofstudents trained by problem-solving and in the tradi-tional way. Overall, I hope that I can teach the problem-solving course in the Fall of 1996.

Conclusion

We have shown that a collaborative learning and problem-solving approach to teaching introductory organic chemistry issuccessful with large multi-section classes.11 We are continuingto refine the method. WWW material is being developed asan additional teaching resource for PSLs and will be availableto students during Spring Session 1998. The importance andresponsibilities of each study group member must be empha-sized and groups encouraged to develop role descriptions foreach member.

Notes

1. We thank Shirley Ann Wacowich for sharing her learningexperiences with us.

2. CHEM 261/263 requires a prerequisite course in generalchemistry.

3. In the Spring Session, the course is taught to a combined groupof freshman and sophomore students.

4. EVB was the instructor for both English and French languageproblem-solving lecture sections.

5. This apprehension appears to be the result of comments fromphysicians, dentists and other nonchemist professionals who completedorganic chemistry prerequisites more than a decade previously!

6. Groups were created in the first laboratory session.7. There were five PNEs in each one-semester course. Each group

submitted one set of answers for each PNE and points were awardedfor scores above 70%.

8. Each course requires 3 hours per week, 11 weeks per term, of

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JChemEd.chem.wisc.edu • Vol. 76 No. 8 August 1999 • Journal of Chemical Education 1107

lab work.9. A typical problem-solving laboratory exercise from the student

laboratory manual and student report book is appended. A copy avail-able upon request.

10. An animated videotape entitled Melting Point Determinations:FAQs (produced by LMB in 1996) shows effective interactive teachingby a TA. This is used in our TA training program.

11. Our methodology has also been embraced at other WesternCanadian institutions, in particular, Okanagan University College.

Literature Cited

1. Venkatachelam, C.; Rudolph, R. W. J. Chem. Educ. 1974, 51,479–482.

2. Kalsai, P. S. J. Chem. Educ. 1976, 53, 553.3. Wilson, H. J. Chem. Educ. 1986, 63, 484.4. Moore, J. W. J. Chem. Educ. 1989, 66, 15–19.5. Pickering, M. J. Chem. Educ. 1985, 62, 874–875.6. Barrow, G. M. J. Chem. Educ. 1991, 68, 449–453.7. Ege, S. N., Coppola, B. P.; Lawton, R. G. J. Chem. Educ. 1997,

74, 74-83.8. Coppola, B. P., Ege, S. N.; Lawton, R. G. J. Chem. Educ. 1997,

74, 84–94.9. Pickering, M. J. Chem. Educ. 1988, 65, 143–144.

10. Cooley, J. H. J. Chem. Educ. 1991, 68, 503–504.11. Sowa, J. R. J. Chem. Educ. 1989, 66, 938–939.12. Wilson, H. J. Chem. Educ. 1987, 64, 895–896.13. University of Alberta Calendar; Office of the Registrar and Stu-

dent Awards, University of Alberta, Edmonton, Alberta, CanadaT6C 2M7.

14. Klemm, W. R. J. Vet. Med. Educ. 1994, 21(1), 2–6.

15. Gabbert, B.; Johnson, D. W.; Johnson, R. J. Psychol. 1986, 120,265–278.

16. Johnson, D. W.; Johnson, R. T. J. Educ. Psychol. 1981, 73, 454–459.

17. Johnson, D. W.; Skon, L.; Johnson, R. T. Am. Educ. Res. J. 1980,17, 83–94.

18. Johnson, D. W.; Johnson, R. T. Cooperative Learning and CollegeTeaching 1993, 3(2).

19. Light, R. J. The Harvard Assessment Seminars, 1990; Harvard Uni-versity: Cambridge, MA, 1990.

20. Cooper, M. J. Chem. Educ. 1995, 72, 162–164.21. Doughert, R. C.; Bowen, C. W.; Berger, T.; Rees, W.; Mellon, E.

K.; Pulliam E. J. Chem. Educ. 1995, 72, 793–797.22. Wright, J. C. J. Chem Educ. 1996, 73, 827–832.23. Felder, R. M. J. Chem Educ. 1996, 73, 832–836.24. Browne, L. M. Organic Chemistry Experiments. Chemistry 161/163,

1998–1999 edition. This manual is available at nominal cost fromthe University of Alberta Bookstore.

25. Browne, L. M.; Auclair, K. J. Chem Educ. 1998, 75, 383–384.Browne, L. M.; Auclair, K. Techniques in Organic Chemistry, Part1 and French translation, Techniques en Chimie Organique, Part1; J. Chem. Educ. Software 1998, SP20; topics are handling chemi-cals safely, filtration, recrystallization: the single solvent method,recrystallization: the mixed solvent method, and thin layer chro-matography.

26. Browne, L. M.; Auclair, K. J. Chem Educ. 1998, 75, 1055.Browne, L. M.; Auclair, K. Techniques in Organic Chemistry, Part2 and French translation, Techniques en Chimie Organique, Part2; J. Chem. Educ. Software 1998, SP22; topics are reflux, using aseparatory funnel, simple distillation, distillation at reduced pres-sure, and using a rotary evaporator.