Beyond the Traditional Lecture System of Teaching Chemistry: Organic Chemistry W. R. Schearer Dickinson College, Carlisle, PA 17013 "His plan of instruction in college was by lectures, which theclasses wereexpected to write in full."So wrote Matthew Bnwn, R student in I'rofessor Nisbet's classes at Dickinion Collere in the early 1790's ( 1 ) . Nishet talked slowly, and the students were expected to write down every word he said and to memorize them for the examinations.' Many of us have not improved our teaching techniques much beyond the lecture method used by Nisbet in the 1700's. Maybe we talk faster and write on the blackboard, or use an overhead projector, but students still frantically try to copy down our words to study for exams. Many of us still spend our class time telling the students everything they should know. Is the traditional lecture method really the best way to convey the subject matter to students? Should not the availability of the material in textbooks make the traditional lecture method obsolete as the major method of transferring information? As students we joked that class was the time when information was transferred from the nrofessor's notes to our notes without anyone doing any thinking. I was always disillusioned when I discovered that the vrofessor's lecture duplicated the textbook. Class seemed like such a waste of time. But some lectures, some classes were great! The professor stopped his "lecturing" and answered questions, or took time to work out a problem while thinking out loud to show us how he thought it through, how a good chemist would work it out. He was thinking, showing us how to think, and then challenging us to think by asking us questions. Sometimes the professor would talk about his research, or he would bring in a newspaper clipping that related to the topic for the dav. But those memorable times were brief. The professor was always pushing to "cover the material". One might conclude from these observatons that the instructor should assign the textbook to students to study on their own (plus problem assignments), then spend class time
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Charles Nisbet was an outstandina Scottish minister and scholar who was persuaded by Benjamin Rush to come to Americato take tne posit on of Pres dent of Dicklnson College, a new insttution ot h gher edbcationat Carl sle. Pennsy vania, on the western fronter of the new United States ~
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doing the fun things: lecturing only on the difficult points, showing the organization of the material, suggesting the best ways to study each topic, answering questions, emphasizing the more important points, working out problems while thinking out loud, or having the class work problems as a group, doing demonstrations, presenting interesting applications of the day's topic, going over questions from last year's exams or from the literature or from industrial and applied chemistry. I did try such a system with a first-year chemistry class some years ago, and it worked very well. The class was alive, attendance was high, scores were high on the ACS exam used as a final exam, and without the burden of having to "cover everything" in class i t was most enjoyable. The chosen textbook covered exactly the necessary content. Then I started teaching organic chemistry. Most of the standard texts available are huge and intimidating. The organization of the material is not as clear to students as it may be in first-year chemistry. And there is so much more material. One cannot in good conscience set loose average and poor students to learn much from the text on their own. They need guidance. As a result most of us apparently go to the traditional lecture method, which gives the guidance by specifying the course content, the emphasis, and the organization. Also, lecturing looks much easier and less time-consuming than any other teaching method. Yet dissatisfaction with the traditional lecture method of teaching organic chemistry has provoked the publishing of a variety of observations and suggestions for improvements (2-14).
T o deal with the increasing amount of material within a lecture context, Kharasch (2) reported on his use of slides and "guide notes" to allow him to cover more material effectively. Levine (3)cites Brewster who reported that when he lectured only on the more important points in the assigned reading and allowed the students to learn the balance of the material on their own, the student's mastery of the material was better than when he tried to cover everything by lecture. Battino (4) and Atkinson (5)both clearly recognized that the real value of class time lies in activities other than the transfer of information. I t is observing an experienced organic chemist, who is also an experienced teacher, as he answers questions and solves problems, appeals to the
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imagination, shows a scholar's mind at work, and transmits his enthusiasm and zeal for the suhject in a way that can not he done in print. A good lecturer does not neglect these items. Students must learn to read and study on their own without expecting everything in the course to he presented or to he paraphrased in class. Battino (4) reported on his "lecture-without-note-taking" system, which he uses for selected topics. Students are assigned the topics in advance. During the lectures no notetaking is allowed. He also found that students liked his "controlled press conference" approach in large classes in which students submit in writine (at least one dav in advance) the questions they would fike answered andihe topics thev would like discussed. He tailors his lectures to meet the requests. A number of writers have reported on wavs to transmit information to students hy ways other than the traditional lecture format so that class time could he made more meaningful. Lamhert (6) suggested two methods. In the first, lectures would he printed verbatim and issued to students at the start of the co&se. Students are required to read and do problems before class. In the second suggestion, he distrihutes a detailed syllabus that has the less important topics clearly labeled. Class then becomes a more useful discussion of the difficult topics. Students are more actively engaged because they know that they will be lost in the discussion if they do not prepare for class. Smith (7) described a lectureless method in which he gives freauent tests and uses class time for discussions and demonstrations. Trahanuskv 181 uses a similar hut more rigid seauence of three classes in a cycle. The first class is mostly lecture. The second class is qukstions and answers, and the third is the examination. For each cycle he distributes a set of printed lecture notes. Harrison (9, 10) and Burmeister (11) have also reported that they distrihute copies of class notes in advance. - ~ Boaz (12),being tired of "lecturing to the tops of student heads", adopted a procedure common in medical schools. She arranged to have an advanced honor student take notes in her classes and sell them to other students. Without the distraction of taking notes, students could concentrate on followine the reasoning- in the lectures. Examination scores improved. Shani and Singerman (13) assign reading and problems to be done in advance. Class starts with a short introduction and ends with a review. Most of the class time is spent with small groups of students solving problems with the instructors available for questions. Morrison (14) argues eloquently both against using class time todictate the course content and for more intellectually stimulating interaction between instructor and students in class. Choosine some of the ideas presented above d u s some of my own, I have developed a teachina method that retains the advnntaees of lecturine but eliminates the drudgery of having to cover all the material in class, yet is flexible, easy to use, and quite effective.= The first problem to be addressed is the huge amount of material in the typical organic chemistry textbook. One must specify what is covered in this course and what is not. Then one must arrange i t in a simple logical pattern that is easy to grasp. I distrihute to students a carefully prepared one-page outline for each major topic. I call the outlines "Study Sheets". ~~
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ORGANIC CHEMISTRY
TOPIC:
STUDYSHEET
CHAPTER: Problems assigned:
I. ii. ill. IV. V.
Nomenclature AnaiyJiSandProperties Reactions Theory and Mechanisms Applied
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A preliminary report on this method has appeared: Scnearer. W. R . In Directory of Teaching innovations in Chemistry. Meeth. L. R.: Gregory. D. S.. Eas: Studies in Higner Education: Arilnglon. VA. 1981; p 363. Currently I am using the textbook by Morrison. R. T.; Boyd, R. N. Organic Chemistry. 4th ed.; Allyn and Bacon: Boston. 1983. Students find this text relatively easy to read and understand.
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The Organlzatlon of the Study Sheets Each major topic (usually each chapter? is outlined consistently in the same pattern, although not every topic will have items under each heading. The best pattern I have found for organic chemistry has five major headings. They are listed in Figure 1.Following each item on the study sheet are the numbers of the assigned problems specifically related to that item. There are numerous advantages to this simple organization. First, i t clearly lays out the suhject matter. A student can quickly get an overview of the material. Second, the arrangement can heused to indicate themajor types of questions students should be prepared to answer. See Figure 2. If the student keeps these kinds of questions in mind as he studies the material, they will guide him to learning it well. The list also indicates that the emphasis is on problem solving, not on memorization, although there certainly is much to be memorized. Third, the presenting of problem assignments adjacent to the pertinent topic gives a student a chance to check her mastery of the topic. If she can not do the problems, she can immediately go hack and restudy that topic. Fourth, the sheet is really a lecture outline for the instruc-
Journal of Chemical Education
Figure 1. &nerd outline of a study sheet. Assigned problems would be listed to the right of each item.
ORGANIC CHEMISTRY
TOPIC: CHAPTER:
STUDY SHEET I. Nomenclature Given the name, write the structure. Given the structure, write the name.
11. Analysis and properties Given a list of chemical, physical, and spectral properties,deduce the Structure. Given several slructures. name tests that will distinguish them. ill. Reactions Given a starting material and conditions, predin the product. Given a compound, propose a synthesis. IV. Theory and mchanisms Given an observation,explain It Given a reaction, propose a mechanism. V. Applied Give a source. Give a practical use.
Figure 2. The study sheet outline with students need to prepare.
major types of questions for which
tor. However, you do not need to lecture on all the material; limit your lecturing to the topics that cause trouhle year after year. I encourage students to record any notes taken during lecture directly on the sheets adjacent to the topics discussed. Here is your chance togat out of having tocover that basic information which students need to know hut could learn on their own, material that is neither an exciting lecture topic nor excitine data for students to copv down. T o write out on the board the names and formulas-of the important compounds that students need to know tends to waste precious class time. Put the material on the study sheet, then go ahead and use the material in class to teach the topics that are annronriate to mend time on in class. ~ L i L k i ; ~and , the requisite concentration that goes with it, is the heart of an education. Collecting and memorizing facts, or, just as had, collecting and memorizing principles, is bv itself. not an education. Students must learn facts and p&ncipl&, hut, equally important, they must learn how to use those facts and those principles. That requires thinking. If you know how to think like a chemist, you can start with your base of memorized facts and memorized principles and do some good chemistry. But if you have just memorized material and have not learned to think, you will never be a good chemist. Thinking, which translates as skill in organic chemistry prohlem solving, is the main point, not memorization of either facts or principles. The use of study sheets frees class time to do those activities which are more likely to stimulate thinking. Fifth, students are encouraged to write definitions and structures directlv on the studv sheets, nearlv. so that the study sheets contain everything they need tostudy for the exams. With everything neatly together, reviewing for the exam becomes simple and is not a chore to be postponed. Sixth, the outline form makes it easy for the student to pick out the qua1 tests, the reactions, and the mechanisms. I strongly encourage students to prepare cumulative lists of these items as weeo through thecourse. These lists are most useful for review15g hefoFe an exam. Since there is much learninevalue in comoiline these lists. I do not nrenare them for stuzents. I do list ihe mechanismson the bo~rdoccasionallv in order to show the maior classifications. Seventh, with the course iontent suapecified, student9 no lonner ask if this or that tonic will be on theexam. Thevsoon realize that, if it is on the Htudy sheet, they had hette;know it. I manage to get over three-quarters of the topics onto the exams eveituany. There is also a shift in focus in the class from the instructor to the material. The instructor is more likely to be seen as a person who is there to help the student learn the material and not as a nerson in an adversarial nosition. as sometimes happens. The responsibility for learning is now more obviouslv on the student. I t has alwavs been thus but now is more clearly so. Uslng Study Sheets A popular way ofstudying nowadays is tosettledown with
a textbook, read it slowly, and highlight the "important" information with a felt-rip pen. This tends to be a long, boring ordeal. However, completinn of the process produces a feeling rhat one has studied hard. Hut, if we take a closer look, wefind that the process is not s t u d ~ i n gbut is a process for idenfrlyin~the material to he studied. The only real studsinr occurs when the student reviews the hiehliehted " mat&izwith the intent to remember it. A significant advantage of the study sheet system is that students do not need to spend hours to highlight the text to identify what needs to he learned. I t has been done; the sheets identify the material. Students just need to learn it. More importantly, there is not that false feeling of security
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from the belief that they have studied the material because they have highlighted the text. One might argue that students should learn to identifv importantmatehal in their reading. This argument may h; correct if the course is based on the orieinal literature and the students are sufficiently advanced t o i e able to recognize the important material. But that is not the case for first-vear organic chemistry students. Let us look more closely atthis point. The primary reason a person takes a course to learn a subject rather than just going to a library and trying to learn the subject on one's own, is that taking a course is a more efficient way of learning. The instructor in a course identifies exactly what students need to study, then leads the students through that material at the most efficient pace, far more quickly than a student could by himself. The study sheets provide a particularly clear way to indicate the course content. A three-sten procedure anpears to be the most efficient way of using the-study sheets.-First, several days before each class students look over the studv sheet scheduled for discussion to get a quick overview of the topic. Then the student should work his wav svstematicallvline hvline throuah the sheet looking up in-the text any i n f a m i l k term, concept, reaction, etc. This is the step where the student uses the textbook. With a specific question in mind, learning is extremely efficient. Students should neatly record definitions and explanations directly on the study sheets. Reviewing the annotated study sheets then becomes a simple, efficient way to review for the exam. No frantic scrambling through scattered notes or trying to read 100 pages of text the niaht before the exam. As each item is mastered, or thought to he, the student should do the relevant assianed ~roblemsto check her mastery of the topic. Should thkre bk difficulty in doing a problem, a rereading of that section of the text usuallv clears up the difficulty. If not, the student notes the difficulty and plans to ask the instructor about that topic in or out of class. 1tell students that it seems to be a Iawbf the universe that anything you hump into that you do not understand will continue to bum0 into vou until vou make the effort to understand it. ~ 6 a ite& t you skipped over while studying alwavs seems to show un on the exam. For maximum benefit of this teaching method, students must look a t the material and try the problems before class. Highly motivated premedical students will readily study before class. Calling on students for help in solving problems may supply enough motivation so more students will come to class prepared. Requiring students to turn in homework (7) or to-turn in notes (9) may help but requires additional faculty time to deal with the paper work. In the second step, students ask their questions in class. Classes are now populated with students who are full of questions. Passive stares are less common. What ajoy! Classes are lively and fun, and we get deep into good material. Step three is the review for regular exams and for final exams. A well annotated study sheet makes review easy. This review should he the third time through the material, three times usually being enough to put most of it into longterm memory. ~
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Preparing Study Sheets
Preparing a set of study sheets the first time is no more difficult than preparing.a good set of lecture notes plus . choosing problemi to assign. There are two differences. Since the study sheets define the course content precisely, be careful that no trivial topics are included, and that every important topic is included. I had my secretary put all the study sheets on our word processor so I could easily proof them. Bound copies were prepared by the college printer and distributed through the college huukstore. In the rollowing years I make minor changes forclarity and to update the material. Every three or four years I like to Volume 65 Number 2
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switch texts or switch t o a new edition, which means a major review of the study sheets to fit the new text. The review is no more complex than redoing lecture notes to fit anew text. If the material was well organized originally, the preparation of new study sheets for the new text goes rapidly. Obviously, if a topic included on a study sheet is not in the text or lab manual, then one must prepare a handout on the topic or be sure to explain i t in class. Actually the biggest chore in switching texts is checking the new problems to assign. Class Activities
Once students get over the initial shock of learning that the textbook is the text for the course and that thev do not have to copy everything down in class, the coursk moves quite smoothly. Student course evaluations a t the end of the year have always been favorable, and often enthusiastic. A typical comment is "don't change anything". The best part is that I really look forward to class. Students are alert and responsive. Time goes quickly. There is a electricity in the air as we do my favorite thing: organic rhemistrv. . ..--.-. a. Instead of talking about organic chemistry and giving students basic information, we go ahead and do organic. Let us look a t some examples. Instead of lecturing on nomenclature of unsaturated and cyclic compounds, I put the structure of beta-carotene on the board and have the class work out the systematic name. Initially they are stunned a t the size of the molecule, but then suggestions come bit by bit until the right name appears. There is a good feeling when the class realizes they can tame a monstrous molecule like that. Rather than lecturing extensively on elimination mechanisms, we do a few. For example, DDT-resistant insects have an enzvme that detoxifies DDT hv doine an elimination reaction. I put the structure of DDT on the board and have the class predict the product and then draw out the s t e ~of s the mechkism. Later in the course we synthesize com~oundson the board from simple starting materials. We make compounds such as cinnamonaldehyde, 2,4-D, benzedrine, aspirin, tvlenol, harhiturates, and a variety of familiar suhstakes.
Note that we bring into class many topics that catch the students interest but that also give us the opportunity to use the organic chemistry we are learning. Many new drugs or other com~oundsin the newspapers are mentioned in class and oftenmade the subject i f problem: how could i t be synthesized? or what would the NMR soectrum look like? Instead of lecturing on qual, I put a fist of qua1 tests and spectral properties on the board (or spectra on the screen) and have the class interpret each bit of information and then deduce the structure. For each kind of problem I first work a few while thinking out loud. I t is most important that students catch the organic chemistry way of thinking and approaching problems. I t is difficult to learn these skills from a text. I t is so much easier to learn bv observine a real oreanic chemist doine real nrohlems. A good tradiiional lec&er will also teach problem solving this wav, .. if he does not omit i t in the rush to cover the material. Actually, what we are trvina to do is save the eood noints of the traditional lecture system but eliminate the dr;dgery of covering material. I am sure that if Nisbet were here todav he would approve. Asample copy of astudy sheet may he obtained by writing the author.
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2. Khruaaeh. N. J. Chem. Edur. 1961,28.280. 3. Levine, a. J. C k m . Edue. 1962.29, 224. 4. Battino, R. J. Chsm. Edue. 1366.43,228. 5. Atkinaon, G.F. J. Ckm.Edur. 1970,47,561. 6. Lamben,F. L.J Chem. Educ. 1963,40.173. 7. Smith,R.B.J. Chsm.Edu. I967,44 14s. 8. Tmhanovsky, W . S. J. Chom.Edur. 198.45.536, 9. Harrison, E.A. In Dimrrary 01 Teaehiw I n n o u o t i o ~in Chemistry; Meeth, L. R: Gregory, D. S.,Eda.: Studies in Higher Education: Arlington, VA, 1981: p3.59. 10. Harrison, EA.; Harrison,A.M.J. Chem.Edue. 197.5,32,654. 11. Burmeister, J. L. In Directory of Teaching Innovoliom in Chomiafry; Mmh, L. R.: Gregory, D. S., Eds.: Studies in Higher Education: Arlington, VA, 1981:p237. ; of 12. Boaz. P. lo Soume Book lor Ckmlatry T e m k n ; Lippincott. W.T., ~ d .~ivisioa Chemical Education, American Chemical Soeiety: Washingtan, DC, 1981:p 119. 13. Shani, A.: Singerman, A.J Chsm.Edur. 1982,69,221. 14: Morrison, R. T. In Placeedinga 01 the Chicogo Conformce an Libem1 Eduotion. Number I. October 18-19. 1985: Rice, M. R.Ed: College Cenkr for Curricular Thought. Univeniity of Chicago: Chicago, 1986; p 50.
An Inexpensive Alternative to Steam Not all laboratories have steam lines. In some that do, the steam lines take a long time to clear the water that has condensed in them since their previous use. As a result, the steam and water are dirty and, often, foul smelling. We have found an inexpensive alternativeto steam and hot water baths. Four-cup (coffeeor tea) water heaters may he purchased for less than $7 each. They are one-piece,sturdy, flameless, have an insulated handle and cover, require minimal additional instruction in their proper use, and heat rapidly. They will easily accommodate a 250-mLround-bottom flask. These units can be used in conjunction with a Power Mite to control the rate of heating. Ben Ruekberg Kansas Newman College Wichita, KS 67213
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