Problem-Solving Teaching in the Chemistry ... - ACS Publications

In the Laboratory

Problem-Solving Teaching in the Chemistry Laboratory: Leaving the Cooks… Christian Gallet Department of Chemistry, Cégep de Rimouski, Rimouski, PQ G5L 4H6, Canada I am a chemistry teacher in a Cégep, a two-year preuniversity-level institution of the province of Québec. Disillusioned by the results of the standard macroscale kits and the usual laboratory “cookbook-formula” teaching methods, I took advantage of the advent of microscale chemistry to turn to problem-solving teaching (PST). A step-by-step description of a problem-solving case given in class shows how this implementation can take place. Students, instructor, and teacher do have to work hard, but the results seem worthwhile. Pedagogical and practical issues are discussed. Scientific vs. “Cookbook” or “Formula” Approach For those unfamiliar with the educational system of the province of Québec, a Cégep (Collège d’enseignement général et professionnel) is a two-year pre-university-level program. A semester lasts 15 weeks, and a regular chemistry course includes a 3-hour lecture period and two 50minute lab periods per week. Our laboratories can be crowded with as many as 32 students. Lack of space compels us to group students in pairs, which allows them just enough room to work, yet respects safety measures. For three years, I taught organic chemistry using the standard macroscale kits, thus following my predecessors’ footsteps. With the usual laboratory “cookbook formula”, I presented my students some lab experiments that had regularly been performed for the past 30 years. Extraction of caffeine, banana oil, aspirin, acetaminophen, etc.— all these experiments were good reliable “recipes” that simply could not go wrong! After three years of macroscale chemistry teaching, I was still uncertain whether I was forming good scientists or good cooks…. Then, just before Christmas 1992, I offered my students the chance to come to the lab during the holidays and perform microscale experiments of their choice. To my surprise, 15 students came and worked in the lab for a week. One even asked me if he could bring along his girlfriend, a high school student. Love being at stake, I agreed to the “bonding” and even supplied her with the laboratory recipe procedure for aspirin. She got a beautiful IR, but could not explain how in the world the miracle came true! I had my answer. The traditional teaching method I was using could allow a high school student to obtain good results, regardless of her understanding of chemistry. And then, when 150 students carry out the same obsolete laboratory experiments during the same week, “student osmosis” in the lab reports handed in the next week is hard to avoid, except from the zealous ones, who work in the solitude of their astronomical IQ. My students could turn out as good cooks, but not necessarily as good scientists! In 1993, I abandoned the traditional teaching methods and turned to problem-solving teaching, with microscale chemistry kits. Why go through such a drastic change that would question everyone’s beliefs and convictions about chemistry teaching? The fact that students could succeed without understanding either chemistry or the scientific method was only the tip of the iceberg: the traditional teaching methods have other drawbacks that can be divided into

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three categories: philosophical, cognitive and pragmatic. Philosophical Objections Traditional teaching is more concerned with the ends to achieve than on improving the means of reaching them. The transfer of information is relegated to a simple accumulation of knowledge through lecturing (magistral teaching), a good means to reach this objective. As soon as one wants to go beyond the stage of raw knowledge, however, lecturing does not suffice any more. It does not develop the students’ critical sense or judgment, nor does it permit them to think for themselves when placed in an unknown terrain (1). We have to remember that teaching is a “complex activity, imprecise, unsoundable, sometimes intimidating and…aleatory” (2). Too often, we underestimate the amplitude of the challenge that consists of preparing students to think for themselves, thus depriving ourselves of the pleasure to fully assist in the students’ intellectual evolution (2). Cognitive Objections To further analyze this teaching model, we must not only comprehend how knowledge is transmitted, but also how it is assimilated. From the cognitive point of view, the traditional teaching model implies that one can memorize and assimilate information independently from its use. David Cohen summarizes our present pedagogical model as follows: “To teach is to narrate, knowledge is facts, to learn is to memorize” (3). In our classrooms, individual cognition takes precedence over exchanges; the manipulation of symbols is more important than the application of knowledge in a precise field (4). As a result, traditional teaching creates surface or superficial learning, characterized by high levels of memorization and student dependence on the professor for the distribution of work (1). Students retain little of what they learn and have difficulty applying what they know (1). Indeed, studies show that during a lecture, students are mentally absent 40% of the time (1). To be more precise, the level of retention is 70% during the first 10 minutes of a lecture, but it drops to 20% for the last 10 minutes (1). According to other studies, after a few months, students forget up to 50% of a magistral course. Since 80% of a magistral course is composed of lecturing (2), one can have doubts about the retention ratio of our science students! In their research on using laboratory instruction in science, Lazarowitz and Tamir (5) remind us of the findings of Hofstein and Lunetta (6) indicating that laboratory activities, as they are currently being implemented, do not enhance students’ learning or understanding of science. These findings are supported by other researchers (5). Pragmatic Objections Pragmatic objections are the end results of the philosophical and cognitive ones. The alarming failure and dropout ratios and the mediocrity of academic results have been

Journal of Chemical Education • Vol. 75 No. 1 January 1998 • JChemEd.chem.wisc.edu

In the Laboratory widely publicized by many authors—in Canada, particularly by Désautels (7). Students dislike the magistral approach; they are rapidly bored and find the matter irrelevant. Whatever the professional field in which they study, they have great difficulty in putting their knowledge into practice (1). When I examine my own three-year experience using cookbook-formula pedagogy, I can identify its weaknesses with regard to what learning chemistry and the scientific method should be. Limits of the Cookbook-Formula Pedagogy 1. The macroscale cookbook-formula experiments do not allow student initiative in the chemistry laboratory. Students often repeat experiments their own parents have carried out: the “eternal” experiments of aspirin and banana oil are good examples. 2. A student can synthesize a compound without understanding the chemistry involved. Sometimes, the student understands the experiment only after it is over, and with generous help from the “osmotic society”. 3. There is no room for student hypothesis and errors; the standard procedure works as a recipe: one has to finish with the right cake. For safety reasons, macroscale kits restrain scientific exploration in college organic chemistry laboratories. 4. The student is not taught to assume his or her responsibility in a group: everyone does the same thing at the same time. Teachers sometimes take for granted that students know how to work in a group, which is far from the truth. Effective teamwork requires active participation from the students, an attitude that is as important to learn as any scientific concept (8). 5. When students work in pairs on the same setup, the teacher has no means to identify which part of the student’s report (or procedure) is an original creation.

Finding new formula experiments is not a solution. The above objections remain. Recipe experiments tend to sterilize imagination and initiative, leave no room for hypothesis, trials, errors, individual responsibility in a group, and above all, preclude the student’s involvement in a decision-making process—which is so important to our modern society. In other words, many parameters that are fundamental to the scientific method are left out by the macroscale cookbookformula approach. A Partial Solution: Problem-Solving Teaching To partially correct the above-stated flaws, all the time keeping in mind the enthusiastic response of those 15 students to the microscale experiments, I turned to problemsolving teaching (PST). PST is not new: it was introduced in the Faculties of Medicine and Commerce at Harvard University in the 1960s, as “case teaching” (2). The method has spread and is now used in some high schools, colleges, and universities, with different variations. It has been demonstrated that information is better understood, retained, and transferred when the student elaborates it (9). PST or its variations lead students to learn in depth; they are more involved in conceptual process than in memorization They study more for the “signification” rather than for reproduction (1). Students are given a problem to solve. To meet this challenge, they have to apply and gather new knowledge, learn to put it into perspective, investigate, make decisions and, very often, work with teammates. Throughout this learning process, the student plays an

active role while the teacher stays in the background. In PST, a problem is not (and should not be) an exercise or the application of a notion. To solve the problem, a student has to acquire new notions: the problem cannot be solved readily by the activation of a student’s previous knowledge. PST establishes an interactive situation in which a student has to assume responsibility in gathering, assimilating, and exchanging new information in a group. In that sense, PST follows Whitehead’s advice that in order to master knowledge, a student “must participate in the pedagogical process…instead of being a passive receiver” (10). The definition of a problem used in this article is that of Hayes (11) and Gabel (12), who state that a problem exists when a person perceives a gap between where he or she is and where he or she wants to be but doesn’t know how to cross the gap. I introduced PST to the lab because it was the ideal place to integrate and apply theoretical notions in a real-world context. A laboratory is propitious to student exchanges and discussions: students can move around freely, try out reactions to confirm a hypothesis. The modification I made to PST is the pilot-experiment step that permits students to verify hypotheses and allows students’ errors, interactive learning, and scientific creativity without threatening the so-important marks. The individual report-writing in the lab is also a crucial step in the evolution of students’ scientific creativity and intellectual autonomy. Students are grouped in teams of 3 and are given a statement or a problem. The problem must be relatively simple and general so that at least 3 solutions (one per student) can be tried out during the pilot experiment periods. Generally, the subject has not been studied in class. The following steps, summarized in the chart and then discussed in more detail, are related to the flow chart (Fig. 1), which describes a problem-solving method developed in parallel with the PST. I made the diagram as general as possible so that it could be applied to a variety of teaching fields. The correction sheet of step 15 could be applied to any science course using the scientific method. First 2 weeks (or 1 week, depending on length of laboratory procedures): First theory course 1. Beginning of chemistry course. Students are placed in homogeneous groups of 3. (They are not aware that I use their previous chemistry course marks to group them “randomly”.) Group secretaries are appointed, who will be responsible for the logbook containing all activities undertaken by the group to solve the problem. This function will be occupied by a different student for each problem. After a few weeks, a class president is elected by secret ballot for the session. 2. Students are given a problem. [EXAMPLE: Some fragrances of fruit come from the presence of esters (names given). Write at least 3 different chemical procedures to synthesize one fragrance. It is strongly advised to check out the physical characteristics and chemical reactivity of all compounds used.] The team discusses the problem to make sure that all members share the same understanding of it. 3. Hypothetical solutions of the problem. The group secretary writes down in the logbook all the theoretical or technical questions and notions necessary to solve the problem. What is an ester? What are the different ways to synthesize it? What mechanisms are involved in each case? Are there any equilibria? What are the quantities of the reactants? Can one predict the relative yields? What are the experimental conditions, dangers, purification procedures, instrumental analysis, etc.? Research is distributed among the 3 members. Each one is responsible for a specific task, which is written down in the logbook. During the week the group meets in the library, gathers

JChemEd.chem.wisc.edu • Vol. 75 No. 1 January 1998 • Journal of Chemical Education

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In the Laboratory the results of their research, and decides which laboratory procedures to try out during the pilot laboratory periods. Each team member chooses a different reaction procedure to synthesize the ester: A, alcohol + organic acid; B, alcohol + acyl chloride; C, alcohol + anhydride; D, alkyl halide + silver carboxylate. Each student writes down his or her own laboratory procedure in a personal lab report. A list of chemicals required is given to the instructor one day before the pilot experiment periods. 4. Pilot experiment periods. At the beginning of the laboratory periods, the instructor has already placed all the chemicals on a cart or in the hoods. Each student is assigned an organic (or inorganic) microscale kit. The responsibilities of each group member are recorded in the group logbook that will be presented at the beginning of the pilot experiment periods. I check the logbooks for safety and individual involvement of the students. Some logbooks have already been checked at my office. No indication is given about the relevance of the different solutions. If a laboratory procedure is wrong, I let the student proceed and find out for himself or herself. During the pilot periods, students try out their procedure, exchange information, and help each other. They have to know how the other members of the group are doing with their procedure in order to decide which procedure they will favor after the pilot experiment. Students know that they need to assimilate the results of the pilot experiments to be prepared for the synthesis of a new compound during the laboratory examination of the next week. After the pilot experiment, the team members meet, exchange results (IR spectra, GC chromatograms, yields, reaction times, etc.), and decide which procedure will be favored for the laboratory exam. One can see how important the individual work is, and how it can influence the team decision. Lazy members are immediately identified by their colleagues.

Third week: Laboratory examination When the students come to the lab, they can be asked to synthesize the compound chosen by the group after the pilot experiment or to synthesize a new one that was not in the list . They choose their procedures as a compromise between the experiment speed and reaction yield, two very important parameters for the exam periods. These lab periods are considered as a laboratory exam. No exchanges are permitted. Students make IR spectra and GC chromatograms of their standards. Since after the lab exam the instructor is usually busy with other classes, I do the GC injections of each student’s product so that students have their own chromatogram for report writing the next week. At the end of the exam periods I keep the individual lab reports for the next step, report writing.

Fourth week: Report writing and correction 1. At the beginning of the lab period I return the lab reports to the students. Students spend the lab period writing their report, which is handed in at the end. Each student writes his or her report individually under examination conditions; silence is required for this part of the PST. All exchanges had to have been done during the previous pilot experiment periods. 2. Each laboratory report is corrected with an answer sheet that is given at the next pilot laboratory period. On the lab report, I write remarks concerning important errors. Marks are written down on the correction sheet. During the

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next pilot periods, the students correct their lab report with the help of the correction sheet.

Semester’s survey and discussion with class presidents At the end of the semester, a survey is conducted with all my students (generally two 1st-year classes and one 2ndyear class). I compile the results in my office and discuss them with each class president. Afterwards, the results of the surveys are discussed with the presidents of all my classes during a lunch period at a quiet restaurant (and I pick up the tab).

Results and Comments from Students I could give figures and results of surveys; but the most relevant support comes from a petition signed by all the students of my two classes. A research project on PST, accepted by the Chemistry Department and the college’s Project Selection Committee, was refused by “higher authorities”. The students’ petition protested against this unilateral decision. Students indicated that the problem-solving teaching method was the most relevant one to help them understand and apply chemical principles. It made them more autonomous and gave them a better preparation for teamwork and research. Eighteen of the 40 students were doing their fourth chemistry course and were able to compare PST with the “classical” method. Discussion

Students’ Point of View In PST, the first lab periods look like “havoc in a beehive”! We have to keep in mind that for most students, this is the first experience in an organic chemistry laboratory. They are placed in an unstable equilibrium, where few answers are given—questions are answered by other questions. Even if they are aware of the method, some students are in a state of shock because their other science courses have accustomed them to follow a well-tuned cookbook-formula lab procedure, where no initiatives were needed and where they could rely on someone else. In my class, they have to not only learn and apply the chemical principles, but also learn how to work in a group and assume the responsibilities bestowed on them by the group. The social pressure is intense. The individual report-writing period in the lab is the most demanding part for them. They have been accustomed to writing their reports in groups (at the college library, I have seen groups of ten students!), more or less copying from each other or getting help for calculation and interSummary of PST Steps (see Fig. 1)

First two weeks: steps 1–12: 1. Students are teamed in groups of 3 in each class. Each class elects a president. 2. During a theory period, the teacher presents the problem to the students. 3. Each team identifies and distributes among its members the parameters and laboratory procedures elaborated to solve the problem. 4. Each student tests one of the pilot procedures elaborated by his team in the previous step and exchanges results with teammates. The team chooses the procedure that is the best compromise between reaction and purification times, yields, and technical skills. Third week: step 13 During this exam period each student tests the procedure chosen by the group or synthesizes a compound chosen by the professor. Fourth week: steps 14 and 15 1. Each student writes his or her report in the lab, under “examination” conditions. 2. The teacher corrects each report and hands out a correction chart containing the answers. Last week of the semester: step 16 At the end of the semester a survey of the PST pedagogy is made in each group and is analyzed with each class president.


In the Laboratory 16

Problem : Develop and validate a laboratory procedure for the synthesisof a compound. The 12 following steps of PST are kept in the group's logbook by a student; turns are taken for each problem. Each student has to write her or his report.

Group activity

1

Key diagram Individual

activity

Definition of the problem Do the 3 team members equally understand the problem ?

2

Correction

"Validation" of the method by a student poll

Decision of the group

3

No

If the results invalidate the hypothesis

Yes

5. Analysis

4

Figure 1. Problem-solving chart for PST.

a) b) c) d) d) e)

Analysis of the problem by the group 1. Identification of the difficulties and the informations needed to solve the problem.

N.M.R I.R G.C.(Tl, P, Col) nD Mp,Bp. ...

TechnicalInformations Theoretical Informations

5

Gathering research results. solutionsto the Elaboration of different problem (synthesis) .

Which procedures are favored ?

7

Report correction sheet 1. Principle: The why and how of the experiment. 2. Hypothethis . 3. Tabulation of data. 4. Observations. 5. Calculations. 6. Interpretations microscopic (at the molecular level ) of the observations. 7. Interpretations of the résults. a-% of deviation. b-NMR, IR, GC etc... 8. Validation of the hypothesis.

8 Choice of experiments

9 Correction of the logbooks We check the individual participationand the security of the lab procedures. No information is given for the validation of the hypothethis.

10

a) Extraction b) Distillation c) Recrystallization d) Chromatography (Gp, P, Tl, Col,)

1. Distribution amongst the group of the different parameters needed to answer the problem. Each member is responsible for the reseach of specific items.

6

Pilot experiments Individual micro-scale experiments are distributed amongst the group. Each member elaborates a procedure and validates one hypothesis chosen by the group.

4. Purification

1. Chemical hazards 2. Phaseof the compound synthesized 3. Experimental Conditions c, t, p, reflux etc... . 4 . Purification techniques 5. Analyticaltechniques

1. Chemical . equations 2. Kinetics(catalysis structure). 3. Thermodynamics (Equilibrium or not). 4. Theoretical yields.

After gathering the results of individual research, the group identifies 3 microscale experiments that could be used to solve the problem.

Distribution of the pilot labs

15

Student 1 does procedure 1


Correction of the individual report with a detailed correctiion sheet presenting the principal elements of the solution of the problem


if none seems satisfying Group analysis of the results of the individual pilot experiments and validationof each

11

Choiceof the best procedure

12

Individual lab application of the solution chosen by the group, orsynthesis of a compound chosenby the professor.

13

Individual report

writing

in the laboratory under "exam" conditions.

14


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In the Laboratory pretation of their results. Obviously they would prefer to write their reports outside the lab with the help of other colleagues! The microscopic interpretation of their observations is the most difficult part of the report. This difficulty is understandable when their previous experience is taken into account. Some students have not been exposed to microscopic interpretations. A common example is the microscopic interpretation of the observation of a boundary phase between two insoluble liquids. Instead of comparing polarity, polarizability, solubilization mechanism, bond energies, they fall back on density differences—which have nothing to do with the solubility process. On the other hand, the majority agree with the examwriting in the lab because they are all placed under identical conditions. Students still can copy procedures in lab textbooks. However, they are aware that during their lab exam, they can be exposed to different compounds requiring different laboratory techniques. They know they have to understand the sequences in their individual laboratory procedure. Students were very satisfied with the correction. The majority of were not accustomed to having their lab reports corrected with a correction chart that they could use as a standard to compare their results. Another interesting result is that the best students in theory are not always the best in the laboratory. Most students are accustomed to having their learning field well defined and structured. Some are completely “frozen” by open questions such as a PST problem where initiative and originality are stimulated. Finally, in a survey asking them to compare the two methods, no student of my 3 groups wanted to go back to the macroscale-cookbook-formula pedagogy they had experienced in other science courses. They think PST should be adopted, developed, and applied to other chemistry courses.

Instructor’s Point of View The first PST experiments were not easy. Instead of having 16 macroscale setups of well-tuned experiments, I had to face a herd of 32 students trying different procedures, asking questions about matters from technical procedures to reaction mechanisms. Complete experimental failures can happen—not to mention students’ brutal nervous breakdowns when everything seems to go wrong. Students are sometimes careless and forget to return things to their place: the lab is dirtier than with classical cook-book pedagogy. More students stay late, since each one has to perform a different experiment and integrate different technical procedures; no one is there to manipulate for them. The number of chemicals used in a PST lab is far greater than in a classical lab, since each student can choose different chemicals instead of performing the same recipe-experiment along with 150 colleagues. These difficulties are compensated during the report writing and laboratory exam periods, during which the instructor (and teacher) have little to do—a soothing contrast to the pilot experiments from which both of us get completely exhausted! Teacher’s Point of View The main objection some professors might have is obvious. In a 15-week session, we experiment with 4 problems, no cookbook-formula. Throughout the province, some colleges have their students write an industrial production of 15 laboratory reports per session! Robinson and Niaz (13) showed that when interactive discussion was used, students performed significantly better than a control group using a lecture format, even though they covered fewer problems than the controls. 76

Problem writing is limited to situations permitting multiple solutions. It must contain new notions integrated in a practical application. Our obsession with covering the most important chemical reactions in the laboratory has to be forgotten. Only 4 situations can be covered in a semester and a crucial choice must be made. When I think about it, how many procedures are we using as chemists? Certainly not all the reactions we have studied! The majority of college students, even if they stay in a science field, will not become “pure” chemists. The professor must follow the students’ progress and be more available than with the traditional pedagogy. Perhaps the most difficult part for me was to let my students make errors without intervening. The problem-solving approach and its resolution method (Fig. 1) implies a drastic change in the teaching mentality. Students put forward hypotheses, become responsible in a group, make errors, exchange information about different solutions, argue, make decisions. The teacher does not give answers, but rather stimulates the students by questioning. Students are actively engaged in the acquisition of their knowledge through an inductiveconstructive cognitive process. The teacher must leave room for errors, hesitations, and sometimes total failure during the pilot experiment. That is what science is made of: educated trials and instructive failures. One has to always keep in mind, as Bunce and Gabel said (12), that chemistry problem solving is a complex human activity. The teacher’s work load is heavier, especially when using the detailed correction chart. The first problem places students, instructor, and teacher in a high state of instability and stress. Subsequent lab problems are generally a breeze: students know what to expect, are more confident, and above all, show scientific creativity that is light-years away from what the macroscale cookbook-pedagogy leads to. The last problem of the fourth chemistry course is a synthesis of the student’s choice. Technical guidance must sometimes be given for potentially hazardous situations— for example, NaBH4 and LiAlH4 reductions, oxidation, or aromatic substitutions. Originality being taken into account, multistep projects (e.g., the cyclohexanol, cyclohexene, adipic acid sequence) are favored, although not always possible. Students can decide on their compounds and procedure (some choices are quite surprising). They work very hard. Each pilot lab is “fun-lab”: students are anxious to try out their solution. Discussions are stimulated, arguments arise: scientists’ brains are at work! No cook is around with a recipe. The enthusiasm and the evolution of the students’ creativity throughout the session are the rewards my instructor and I get for the extra time and energy we invest in these classes. After the first problem, organic chemistry is transmuted into “fun chemistry”. I can see the improvement in my students’ interpretive capacities in the second problem. They are not afraid to try some logical interpretation even if they are uncertain, since I give marks more for logic than for truth. This section of the report is one of the most relevant tools for following the students’ scientific originality. Conclusion The PST method is one teaching tool among many. In my opinion, it develops students’ scientific initiative, creativity, and communication skills. It allows room for students’ hypotheses and errors, teaches them to assume responsibility in a group, helps them in decision making, and develops their autonomy in writing lab reports. I think that developing imagination, scientific creativity, and intellectual au-


In the Laboratory tonomy is far more important than the accumulation of cold knowledge, and I find that these abilities are more developed by PST than by my previous teaching approach. PST follows Lazarowitz and Tamir’s definition of a laboratory experience (or problem, in this case) (5). It should be structured so as to present a “puzzle”, not an illustration of what students already know; it should include topics for which current knowledge is incomplete. Students should be required to prepare a plan in advance for how to proceed, rather than using manuals and written instructions in laboratory works. They should be required to write reports using a very flexible format. Only with discussions, interpretations, inferences, and conclusions do experiments play a meaningful role in learning (5). With PST, the laboratory can be used to identify students’ preconceptions and to extend or modify such conceptions (5). A variation of the PST I introduced in 1993 has been applied in the theory classes of a combined chemistry–biology college final course (1996 January–May semester). This is a strong positive indication of the college’s opinion about PST! Acknowledgments I would like to thank the Chemistry Department of Bowdoin College and particularly Dana Mayo and Ronald M. Pike (from Merrimack College), who introduced me to microscale organic chemistry—which permits a pedagogical versatility never reached before (14–17). PST and its problem-solving method (and this article) would not have been possible without microscale techniques. I kept my promise: microscale chemistry is implemented at the Collège de Rimouski and is there to stay!

Literature Cited 1. St. Jean, M. L’Apprentissage par Problème dans l’Enseignement Supérieur; Université de Montréal: Montréal, 1994; pp 21–22. 2. Christensen, C. R.; Garvin, D. A.; Sweet, A. Education for Judgement. The Artistry of Discussion Leadership; Harvard Business School: Boston, 1991. 3. Cohen, D. K. In Contributing to Educational Change: Perspectives on Research and Practice; Jackson, P. W., Ed.; McCutchan: Berkeley, CA, 1989; pp 27–84. 4. Resnick, L. Educational Researcher 1987, 69(9), 13–20. 5. Lazarowitz, R.; Tamir, P. In: Handbook of Research on the Science of Teaching and Learning; Gable, D., Ed.; MacMillan: New York, 1994; pp 94–121. 6. Hofstein, A.; Lunetta, V. N. Rev. Ed. Res. 1982, 52, 201–217. 7. Désautels, J. École + Science = Échec; Québec Science Éditeur: Québec, 1980 , p 283. 8. St. Arnaud, Y. Les Petits Groupes, 2nd ed.; Université de Montréal: Montréal, 1989. 9. Norman, G. R.; Schmidt, H. G. Academic Medicine 1992, 67, 557– 565. 10. Whitehead, A. N. The Aims of Education and Other Essays; Free Press: New York, 1929; p 30. 11. Hayes, J. R. The Complete Problem Solver; The Franklin Institute: Philadelphia, 1981. 12. Bunce, D. M.; Gabel, D. L. In Handbook of Research on the Science of Teaching and Learning; Gable, D., Ed.; MacMillan: New York, 1994; pp 301–326. 13. Robinson, W. R.; Niaz, M. Int. J. Sci. Ed. 1991, 13, 203–215. 14. Butcher, S. S.; Mayo, D. W.; Pike, R. M.; Foote, C. M.; Hothman, J. R.; Page, D. S. J. Chem. Educ. 1985, 62, 147. 15. Szafran, Z.; Singh, M. M.; Pike, R. M. J. Chem. Educ. 1989, 66, A263. 16. Chloupek-McGough, M. J. Chem. Educ. 1989, 66, 92. 17. Gallet, C. Lignes Pédagogiques, Collège de Rimouski 1993, 6(2) 15.


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Problem-Solving Teaching in the Chemistry ... - ACS Publications

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