Group Discussions in the Chemistry Classroom and the Problem-Solving Skills of Students J a m e s L. Fasching Department of Chemistry, University of Rhode Island, Kingston, RI 02881 Bette LaSere Erickson Instructional Development Program, University of Rhode Island, Kingston, RI 02881
A general claim of all introductory science courses in the country is that they teach knowledge, understanding, and the application of scientific theories and experimental procedures. These learning outcomes supposedly provide the foundations for using the scientific method in reasoning, problem solving, and investigating. Unfortunately, these claims and suppositions are not altogether warranted. For these authors, they are most clearly revealed in what students can and cannot do after they have completed their introductory science courses. For example, students who complete a typical introductory chemistry course appear quite able to recall important definitions, theories, laws, experimental procedures, and formulas. They can answer correctly questions such as, "What is the equilibrium constant expression for a weak acid such as acetic acid?" Most students can also oerform calculations and solve problems using the materiai they have studied if the problem explicitly states or strongly implies which concepts, theories, and formulas are t o he used. More often than not, students successfully solve problems such as the following Given the followingequilibrium expression, what is the hydrogen ion concentration (pH) of a 0.1 M acetic acid solution?
However, if we embed the same information in a problem situation-without making the necessary relationships explicit, without identifying the concept or rule to be used, without stating which formula is needed-then students act as if they have never seen such a problem. For instance, alarmingly few students are able to solve the problem below, even though i t requires understanding of the same concept as the previous problem and even if the instructor had listed hoth acetic acid and propionic acid as weak acids: What is the hydrogen ion concentration (pH) of a solution that is 0.1 M in both propionic acid and sodium propionate? Moreover, it is a rare student indeed who demonstrates the ability to approach (much less solve) a complex problem which requires the selection and the use of more than one or two contents. A problem such as the followine leaves most introductory chemistry students staring dazeily, searching throunh their texts for similar oroblems. or waitina for their professors to give them some ciue aboutwhere to begin: A chemist on a chemical processing line wished to calculate how much NaOH solution to add t o a given hatch of chemicals that had both HCI and acetic acid in it. The solution was 2.0Min HCI and 0.2 M in acetic acid. How much base should she add per liter of solution so thst her final solution is 0.1 Min acetic acid? What is the pH of the final solution? (Ignore volume changes.)
ing students much about scientific methods of investigation when one witnesses the naralvsis . amone students if thev are asked, for example, "to design and conduct aseries of experiments for the determination of . ~ h o s.o h a t ein various detergents." Of course. none of this should surprise anvone. since most introductory science courses cmphnsize precisely rhuse comuctenries which students develou: thr ahilirv to recall information and to use it as d i r e c t e d h solving problems. Texts, lectures. and demonstrations present the information that students are to memorize. T o be sure, the questions posed in class, a t the end of each chapter of a textbook, and on exams ask students to apply their knowledge in solving problems. However, these questions usually provide strong hints about what information is needed inorder to solve the nrohlems. In fact, most of these problems merely require students to "plug numbers into formulae" and to perform calculations. Similarly, laboratories provide dramatic demonstrations of oarticular laws and eive students ex~eriencein performing experimental procidures. Rarely, however, d d t h e y involve students in the puzzlinn process of scientific investigation when "you have not heen told exactly what you are supposed to do" or "you do not know how things are supposed to turn out."In short, despite claims that introductory science courses seek to develop skills in using the scientific method, it is difficult to find instructional materials or methods which engage students in such activities. Five vears aeo. the authors set out to redesien the second semester port& of a two-semester introductory chemistry course for chemists and chemical ennineers at the University of Rhodr Island su thst the ct~urscmight be more consistent with its cl;llm to stress rhe scientific method, problem solving, and reasoning. The remainder of this paper describes changes made in the course and reports the impacts on student achievement and student ratings of the course.
Course Descrlptlon Initial efforts to revise the introductorv chemistrv course were guid(,d by the three primary principles. It was assumed that studeuti would br more likels to accomplish the obiectives if (1) they were told in understandable terms what those objectives were; (2) they were given opportunities to practice the skills and behaviors described in the objectives; and (3) exams and other evaluation procedures actually measured performance on the objectives. Efforts to tell students about course objectives sought to stress the scientific method rather than the list of topics to he covered in the course. Thus, the instructor (JLF) provided the following introductory statement on the syllabus: The foeor of the .~ course will he -~ concerned with vou develooine ~. . a better undersronding uf chemistry and the wavs in which chcnni h usc i t . The hnsic frumework for nll rhr activities in ~~~~~~~~~~r will be the scientific method and/or an aspect of the scientific ~
In the laboratory, students seem lost if their professors fail to provide step-by-step directions for experiments. It is difficult to hold onto the notion that laboratory work is teach842
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method. The scientific method can be summarized in the followins outline: Observation Hypothesis Formation
While such small group discussion activities provided practice for particular scientific reasoning skills, they did not require students to practice the combinations of skills
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~a~erimentatioh andlor Testing Theory Formation
Table 1. Typical Group Dlscusslon Problems
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DiSCUSSlon Group Problem A
('sing rhisuutline us a framrwork, J1.F acknowledged that students u,uuld need to commit some information 11) memory and that they would be required to perform calculations and other operations similar to those they had done the nrevious semester. However. memorization and calculation - ~ u,ould plov a minor role. Initend, the most important goals involwd the abilitv. to nuulv .-- the course marerial-the ability to apply it when making observations, formulating hypotheses. ~. r o.~ o s..i nexneriments, e. explaining .experimental data, making predictions, and or drawing conclusions. With these coals in mind, a wrirty of instructimal activities were developed for the course. TO be sure, JLF continued to assian readings, present lectures, and conduct recitations in o;der to i&&duce and explain the material. In addition, small group discussions became a regular feature in class meetings. While J L F often spent the first part of class lecturing, students spent at least half of each meeting in small groups (5-6 students) discussing problems. Sometimes the problems were presented in written form. More often. J L F nerformed an exoeriment or asked students to perform onein their groups, advised students to record their ohservations. and then asked the groups . - to use what they had learned t o explain their ohservations or formulate hypotheses or propose additional experiments. In one class, for example, students were divided into groups and were given the following task Dii,ol\,r the NH,CI in the brakrr that isgwen to your group with water. I'Iaee o few drops ~f water on the damp ipvngr and set the beaker on it. Discuss and explain your ohservations using thermodynamic and chemical reaction theories ~
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Scientific Observationand Explanation A) Three Solutions A. 0 , and C. 8) Various Experiments Performed by Instructor. C) Discuss and Answer the FollowingQuestions: 1) How many species in each solution are needed to explain the experimental facts? 2) How many compounds? 3) Are the various bonds ionic or covalent? Can you answer this question? 4) Using A, 0 , and C, write the chemical reactions for the observed phenomenon. Discussion Group hoblem 8
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As students conducted the experiment and discussed their observations, J L F moved from group to group, noting each group's progress and offering guidance when students needed it. Although the small group exercises had been introduced ~ r i m a r i l vin order to provide practice in scientific reasoning, increased student-instructor interaction and indi\,irluulired heln werr among the bonuses which the method u e class d and asked offered. After =.20 min, ~ ~ ~ i e c o n v ethe several ZrouDs . to report. The remaining time was used to compare, contrast, and discuss the strategies various groups had used and the explanations they had considered. The session on redox reactions illustrates a variation of the same basic instructional approach. J L F asked the groups of students to observe as he mixed various combinations of three unknown solutions. (See Table l-A for the student handout concernine " this eroun discussion.) After each experiment, students' observations of precipitation, color chanees. and elansed time for the reactions were recorded on the biaid. J L F then asked the group to formulate hypotheses to explain these data. ~fter-5-15min, several groups suggested further experiments, which J L F conducted. At this point, hypotheses tended to be statements such as, "I wonder what happens if you leave out a reagent?" Students then returned to their small groups for morediscussion using the results of both sets of experiments. When students finally succeeded in verifying their hypotheses, they had experienced both the procedures and the spirit of scientific discovery and the inherent satisfaction felt by all scientists when experiment confirms hypotheses. In fact, each year this class has elicited cheering and handclapping from students. Additional examples of group discussion tasks are listed in Table 1.
Consider the Experiment of Lord Rayleighwhere he prepared batches of N* from chemical compounds and measured the mass required to fill a certain flask. He also repeated the same set of experiments for dry, carbondioxide tree air by using different methods far removing D2. The 10 batches of "chemical N," have an arithmetic mean of 2.29971 g and 9 batches of atmospheric-NZhave an arithmetic mean of 2.31022. The overall s value is -0.00030 f w both experiments. Answer the following questions: 1) ISthere a significant difference between these two averages? 2) IS the resulting ratio chemicallstmosphere-N2significantly different from 1.0000? 3) What is the largest percent error one could have and still come to the same conclusion as in question 1 (at 99% confidence level)? 4) Explain Lord Rayleigh's results in terms of known chemical facts. Discussion Group Problem C A chemist used a gravimetric and volumetric method to analyze for Fe in two more samples. He obtained the following results far six analyses for each memod. Sample 1 Gmvimetric (%Fe)
Sample 2 Volumetric (%Fe)
1 6.56 7.33 2 6.60 7.43 3 6.50 6.83 4 6.46 6.93 5 6.52 7.10 6 6.54 7.16 Answer the following questions: a) Are t h w two samples significantly differemhom each other? (95% C.L.) b) Are the two methods significantlydifferent from each oms? (95% C.L.) C ) Discuss the ramificationS of trying to anwer the above two questions with this experimem and design a better one requiring the same smoum of w a k . Discussion Group Problem D 1) 2) 3) 4)
Compare and contrast the two different physical models. What are the advantages of each model? What are the disadvantages of each model? Are any of these models a true representation of the real moiecule? (Include the octet rule model.) 5) Why do we use models? Discussion Group Problem E GROUP 1 2 3 4 5 6
METAL Li Cr Ag Cr Na Ca 7 K Design a battery using the assigned metal and anylhing else an the electromotive table. 1) Give chemical reactions. 2) Give some physical characteristics. 3) Worry about the capacity of the battery. Try to get the highest voltage. Banus: Iwill treat the group with the "best" deaign to a scda next week.
Volume 62 Number 10 October 1985
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involved in scientific investigation. Thus, a group research project was added to the course requirements. The project required each group to define a chemical problem or question, to desian an exwerimental orocedure. to conduct the experiment(& and td prepare both a written report and an oral wresentation of their work. Each research arouw included five or six students. J L F appointed a &dent lezder (based on student performance during the previous semester) to organize group members, direct their activities, and report their progress. For most freshmen, this project represents a first attempt to conduct a scientific study from start to finish. Initially, many students perceive the assignment as ambiguous, unstructured, and generally unsettling; they need guidance and frequent reassurances. In order to provide some initial direction, J L F distributes the list of suggested experimental methods presented in Tahle 2. In ndditim, group progress is checked several times durinp the semester. During the sixth week of the course, each group must submit a written definition of the question or problem it intends to investigate. J L F reviews these statements, notes questions or suggestions, returns them to students, and usually requests revisions. Once groups have defined accewtable oroblems or ouestions. each m o m is asked to suhmit'an &line of the eKperimeital p&edure to be used. Aaain. wrowosals. returns them with . J L F reviews their . . questions or suggestions, and again usually requests revisions. BY the time students begin work in the laboratorv, they have already been assured ;hat their topics and experi: mental procedures are acceptable, that their projects are
Table 2.
List of Grouo Proiect Methods Used bv Students
1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17)
Determination of Phosphate in Detergents. Determination of Phosphate in Natural Waters. Amino Acid Separation and Determination. Determination of Citric Acid in Fruit Juices. Determination of Buffering Capacity of Antacids. Determinatian of Various ions in Natural and Tap Water. Determination of Percent Ethanol in Beer. Determination of Percent Ethanol in Whiskey. Determinatian of Dissolved Oxygen in Seawater. Determination of Percent Ethanol in Urine. Comparison of Volumetric Analysis versus Gravimetrie Analysis Analysis of Tea. Determination of Lead in Gasoline. Determination of Zinc, Calcium, and lron in Blood. Determination of Creatinine in Blwd. Analysis of Cumberlandite. Assay of Pharmaceuticals. a. Terpin Hydrate b. Vitamin Pills C. Chiorothiazide 18) Determination of Lead in Dinnerware and Pottery. 19) Determination of iran in Biood (effects of iron pills). 201 Determination of Drum in Urine. 211 Determml on of ,rea m a Gl~cosen Blood or Urine. 22, Determlna! on of Asporon and Sa icy ales :n Blooa. 231 Assay of Asp r n in Varmls Med ca Preparations. 241 Detorminal on of M e r c q on SeafoW 251 Determinat on of Copper. M e r c ~ vand , Chromium In Rover Sed menlo. 261 Assay of Special K '*Breakfast Cereal for Proten Fa!, etc 27) Determination of Caffeine, Acidity, Preservatives in Carbonated Beverages. 28) Determination of Cholesterol Level of Biood versus Cholesterol intake. 29) Determination of Ethanol, Aldehydes, and Carbohydrates During Fermentation of Grape Juice. 30) Determination of Acidity of Coffee. 31) Determination of Chloride in Tap Water. 32) ion-Exchange Capacity of Water Sonners. 33) Reclaiming Ag2+. 34) Computer Simulation of any Chemical Concept1 35) Protein Content of Fwd. 361 iron in Me B l w d of Men and Women.
844
Journal of Chemical Education
significant, and that they are manageable in the time available. The last six scheduled laboratory meetings are devoted to the group research projects. Still, students spend many additional hours in the lab. In fact, most of the group projects have required 175-200 h to complete, so individual students typically commit 30-40 h to the research project. Tahle 3 lists the projects which students proposed and completed in 1 QR2
The introduction of small a o u .u discussions and the " erouo. research project had costs, of course. Appropriate discussion wroblems and exercises had to be develowed. Although these can be re-used each year, they nonetheless take time to create and refine. Moreover, the discussions and group research work used class time. J L F had to reduce the amount of time he lectured, which was accomplished by converting much of his lecture material to discussion problems. Still, some detailed content had to he dropped from the course, although fewer topics were sacrificed than one might imagine. It appears that students catch on to new material more quickly when they truly understand material covered previously. In any case, the development of scientific reasoning, prohlem solving and research skills was the important goal; it was assumed that students needed to practice these skills-not memorizing more and more facts-and, each semester, more and more time was devoted to the small group discussions and zrouw . . research uroiect. Finally, evaluation procedures had to be revised so that they were consistent with course zoals. Written examinations and quizzes continued to be primary means of measuring student learning, hut all exams and quizzes were "open-book, open-note." Not surprisingly, students could recall most of what they needed to know; but the policy was introduced in order to de-emphasize the role of memorization. Instead, exams sought to test students' abilities to
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Table 3.
List of Group Prolect Problems In 1983
Group l We will determine the effects of zinc tablets by measuring the % Zn in blood before taking tablets and aner..Two people will not take any tablets to establish a control. Omers will take different amounts of Zn each day. Group 2 Delelm nation 01 the healtn aspects in caroonalea neverages by comparf01 ac d ty. Determine the inrake of cenain acids, i e phosphwlc acid. hydrochloric, and sulfuric from the amount of soda a person consumes.
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Group 3 is spring water worth payingfor? Arethere really benefits to drinking spring water or mineral water over tap water? ions to be determined are F, Ci, Br, I, Na. K, Mg. and Ca. Group 4 Determine the phosphate distribution down the Pawcatuek River. We will aaempt to generate hypothesis to explain any differences in the distribution. Group 5 IS there a loss of calcium when using the skim miik as opposed to whole miik? If so, what is Mat lass? Group 6 What amount of protein is available for consumption in one week at the dining hail? Also compare Me amount with the suggested level of intake. Group 7 Do women use iran faster than men? Determine iron in b i w d (wlo supplements). Take supplements for 1 wk, or a given period of time. Redetermine iron in blood. Compare differences in lron levels of men and women. Group 8 Which cola gives Me most caffeine for your money? We will use some method to determine the percent caffeine in various colas. Colas to be compared are Tabg. Cokee, Pepsi". C8Cm. R.C., Stop & Shop. (This list may " B . "
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apply course content in a variety of situations. Some questions were relativelv simple, resembling those found in most introductory courses and texts. For example, students were asked A 63.24-ml sample of FeSO*solution requires 41.38 ml of 0.1028 N Na,CrrO, in aid solution far titration to ea. ~ t(a) " . .. Write a bal-
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aneed redox chemical equation. (h) Calculate the normality of the FeSO4 solution. and
If the activity of a radioactive sodium source after three days of half-life = decay is4.3 X 105dps,what was its initialacti~ity?~'Na 14.8 h. More difficult were questions which presented problems in unfamiliar terms, but which indicated the concepts or theories or relationships needed to solve the problem. For instance, the following question poses a problem which would he unfamiliar to students, but which mentions the concepts to he used: I t is oftrn wid rhnr nrnr room tpmperature, n reaction raw doublrs if rhe rempernturers increased by 1UoCCalculate the activation energy of a reduction whose rate exactly doubles between 2I0C and 3I0C.
Most difficult were exam questions which (a) presented a novel situation; (b) did not identify the concepts or theories or relationships needed; and (c) required the use of two or more concepts or premises. Students encountered several problems, such as the following: Campers on a mountain pass at 3 km (9840ft) altitude experience an atmospheric pressure of 0.69 atmospheres. Their pure water hails at 90°C and they discover that it takes 30 min to make a "three-minute" egg. What is the ratio of the rate constants for 100°C versus 90°C? The +olubilityproduct ofsakiurn hydroxide is 1.3 X 10-6nnd the su1uh:lity pruduct of lrud hydroxidr is 1.2 X lo-". 1.00 L uf a iulution :*O:25 .+Ii u l'b2' and U.5 1 in Ca2'. A 1.00 Maolutionuf NaOH is added to the above solution until Ca2+begins to preeipitate. What is the volume of NaOH solution added? Exams and quizzes were constructed to sample and measure students'ahilities to apply course content in avariety of situations, ranging from &tively simple and structured situations illustrated in the first problem to the complex and not so clearlv structured situations illustrated in these last two problems. In addition, the group research project provided ameasure of students' abilities t o use chemical knowledge and the scientific method "in the way chemists use them." These were graded in the wavs chemists are "maded." Thus, grading criteria included ;written report of8-12 pages and a 15-min oral uresentation which were all presentk d k the last two days of classes. While the content covered in the introductory chemistry course was not changed much, the course is nonetheless dramatically different from the way i t was five years ago. In 1978, the course goals emphasized memorizing and solving fairly simple problems. Since 1979, course goals have stressed application, scientific reasoning, and complex prohlem solving. Whereas lectures and conventional laboratory experiments used to be the primary methods, roughly 50%of class time is spent in small group discussions and a third of the lab sessions are devoted to the group research projects. Examinations now ask students to analyze data, to design experimental procedures, and to solve complex prohlemschallenges which did not appear on examinations five years ago. Results Efforts to determine the impacts of these course revisions on student learning have been difficult, and the evidence
remains largely impressionistic. Since exams and laboratory work posed challenges which had not been posed before the course was revised., ore-oost . . comaarisons are not aossible. Instead, student performance on exams and on the research projects have been monitored carefully, and these results have been encouraging. Most students are able t o handle the simale and the moderatelv difficult a~olicationuroblems inciuded on exams. ~ 1 t h o ; ~ hnot all sibdents su~cessfully solve the more complex problems, many students show signs that they know what they are doing. The group research projects have been consistently excellent. In fact, the authors believe they are comparable in quality to research performed by first-year graduate students. In 1982. the authors set out to document some of these observations. At the beginning of the semester, students were eiven a oretest. which included the four auestions discussei in t h e introductory section of this paper. Since the chemical concepts required to answer the pretest questions had been covered during the first semester of this introductory sequence, the pretest was intended to measure students' understanding and skill in applying those concepts. As predicted, most of the 50 students answered the first and secbnd questions correctly, confirming suspicions that freshmen chemistry students are able to recall information and when needed relationships are given. Howevsolve er, only 14 students correctly answered the third question, which reauired students to select and aoolv a sinele conceot. Only one student seemed to know how to approach the fourth auestion which reauired the selection of two concepts and their application in a sequence. At the end of the semester, students were given a post-test which included questions comparable to the secodd, third, and fourth uretest questions. Of special interest was student i o n s , included on themost ~ o m ~ l e x ~ ~ u e s t which the following: .&
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1 ) T l e amuuni of calcium i u blood sampled ma) be drrrrmined by prrcipitaring it as CaC1O,. This pmipitatr may fhrn be dissolved i l l H SO1and rhr C.0; titrared with standard KMnO,
solution. Foilowing this procedure, 10.00 ml of blood are diluted as CaCoOa to 50.00 ml. and then the Ca2+is oreeioitated . . . .from a 10.00ml poruon thrs diluted sample. This precrpitnte, when wnrhed and rlrrsdved m H.SO,, r q u m s 1.63 ml of 001)?3U N K.\lnO, fur t:trntr,n. How many mill~gramvuf C'a-' were in t h e 10-mlsample of blood? 2) The solubility of BaC03 in water is greater than that calculated hv* usine* the listed R. -,.value. a) Account for this behavior. b) Give chemical equations to support your explanation. c) What is the actual solubility of BaC03? d) Calculate the solubility of BaC03 if 1 L of solution is in equilibrium with 0.5 atm of COz. :I, Crenre an rxperimcnrnl procrdurr with details whprphy the )on. iratiun ronsranr iur an unknoun weak monopwrir bnse ran he determined from the titration curve for that base (a pure sample of the unknown base is available). Figure 1presents the numher of students who answered each question totally correct, partially correct, and missed completely. At first glance, these results appear disappointing; they do not indicate that all students can solve complex problems by the end of the course. However, virtually none of these students knew how to approach such problems a t the beginning of the semester. At the end of the semester, about 40% had some idea about how to proceed and were able to provide partially correct answers. These results, combined with similar results on course exams, do suggest -- that students develop reasoning and problem-solving skills. Student evaluations of the course provided a second means to assess the impacts of changes made in the course. In 1979,1982, and 1983, students were asked to complete the Teaching Analysis by Students (TABS) questionnaire. Students' overall ratings of their instructors for each of these Volume 62
Number 10 October 1985
845
Figure 1. Post-test results forihe three most complex questions (textgiven on page 845). The z-axis is the number of students.
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Figure 2. The Teaching Analysis by Students (TABS)ratings of the instructor for the fiveyears. Each city block represents Ihe percent of students in e given year that rated the instructor as belonging in the class stated an the x-axis.
years are presented in Figure 2. Figure 3 presents students' overall ratings of the course in the same years. The most obvious, hut nonetheless striking, observations to he made from these data are that student evaluations of their instructor and of the course have improved dramaticalIv since 1979. Whereas onlv 15% of the students rated the instrudor nlwve average in'1979.70Pi of the 19W class rated the insrructur " m e of the most effecti\,eUor "more effective than most." In 1979, only 40% rated the course better than satisfactory; in 1983, 70% of the students rated the course "excellent" or "good." The distribution of student responses to the more specific items included in Section 1 of the TABS questionnaire showed similar patterns of increasingly favorable ratings. Of particular interest were students' evaluations of their instructor's skills in "making effective use of class time," "maintaining an atmosphere which actively encourages learning,""inspiring excitement or interest in the content of the course." "usine a varietv of teachine technioues." "asking thought-prov&ing ques"tions," and''gettingstudents to participate in class discussions." Responses to these items were extremely positive and represented the most dramatic improvements over the ratings in 1979. They were also noteworthy because it seems likely that increased interest in the subject and more discussions of ~ r o h l e m resuirinn s scientific reasoning largely account for the improvements in student performance discussed earlier. Concluslon Five years ago, the authors set out to revise the introduc-
846
Journal of Chemical Education
Figure 3. The TABS ratings of the course for the five years. Each city black represents the percent of studems in a given yew that rated me course as e~~ellent, gwd, fair, etc.
tory chemistry course so that it might make good on its promises to help students develop scientific reasoning and prohlem-solving skills. Originally, i t was assumed that students would he more likely to achieve course ohjectives i t (1) they were told in understandable terms what those ohjectives were: (2) thev were eiven o~oortunitiesto oractice the intellectual'beha'iors described in the ohjectiGes; and (3) evaluation ~roceduresactuallv measured students' ~ e r f o r mance on tiose behaviors. MO&of the changes introdiced in the course were based on one or more of these assumotions. Evidence drawn from students' performance on examinations and from students' evaluations of the course suggest that the course is more successful in enabling students to develop their scientific reasoning and prohlem-solving skills. There were, in the course evaluations, hints that some students' views of knowledge (especially, their views of scientific knoa,ledye), their rxpectations of science instrurtors, and their perceptions of rheir responsibilities as scicnce srudents reseml~lethose which characterbe student3 in positions 01 Dualism.1 'l'hus, efforts ru detrrmine the devrhpmental position%of students enrolled in the freshman chemistry (.OUKenow seem particularly urgent. It' it turns out that the 20% or so of the student^ who find this course and the insrructiun t'rus1r;tting are in positions of l)ualism, then the assumprims whish have guided efforts to strenrthen the courseare probably not ~Gfficient.If such students are to understand the challenges posed in the course in the same way that their instructor understands them, if they are to profit from the opportunities to practice reasoning and prohlem-solving skills, and if they are to succeed in achieving the ohjectives, then supports will need to be available so that students will risk a transformation in the wav thev perceive knowledge and view the pursuit of knowledge. such sunuorts are likelv to take different forms from those introduced in the course to date and from those suggested in many current proposals for improving science education. Acknowledgment The authors wish to acknowledge and thank all the students during the last five years who allowed the authors to "experiment" with their education and graciously completed the evaluation questionnaires.
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' Perry, W. Jr., "intellectual and Ethical Development inthe College
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Years." New York: Holt, Rinehart, and Winston, 1970.
