David W. Brooks University of Nebraska-Lincoln, Lincoln. NB 68588 The Traditional Large Lecture Session As a student of the profession of teaching, I have watched many teachers give classroom lectures. Mostly they talk and write a t the board or overhead projector. Although most lecturers would disagree, there are actually only occasional times when they ask or answer a question. Class size is often an issue when teaching is discussed. While we can image one-on-one teaching, or teaching in small groups, much chemistry teaching is done in large groups. The classrooms that I have most recently worked in hold over 200 students, and they are not the largest of lecture halls. What is it like to be one among the group in a very large lecture hall? I think students are easily lost. Some say the large universities attract students whose style favors the anonymity of large classes. Most of the students, I suspect, have little idea of what they face in college, and few really appreciate these large classes. This paper concerns activities we can use as alternatives to traditional, large-class lecturing. Lecturing is fun. When you are good a t it, lecturing is fun for both the lecturer and the lecturee. Popular lecturers are clear, tell good jokes, respect the class, and provide structure. By respect the class, I mean that they take the students to be serious about learning. At best, providing structure by a lecturer usually involves indicating to students the parts nf the text to he skipped. At worst, it is telling stlldentsexartly what ison the exams so that recall without orocessine can lead them to success. The realitv of the human conditionk that all learning demands structurl. When you give lots of structure for a problem, performance on the problem improves. The term often used by critics to describe orovidine structure is sooonfeedine. ~ m o n gmy alternatives to traditional lecturing I find no alternatives to texts. Obviouslv texts alone do not lead to learning. If they did we would n i t have schools-just examinations and examiners. Remember, many lecturers' main contribution in class may he to tell students which parts of the hook will be covered on exams. Canned Lectures In my course we add structure to the text using canned lectures ( I ) . This includes lap-dissolve slide programs, classnotes, detailed assignments, and help coordinated between assignments and available resources. About 50% of the available lecture time is devoted to presenting "canned" materials. Two, three, or four modules lasting an average of 8 min each are shown each period. All canned lectures are transferred from slides to vidwta~e. and are available for very detailed review of the content &e: sented. There are student notes for every lecture. The notes contain assigned problems, worked-outanswers, and references to help. The notes provide support for in-class experiments. Almost everything is in the notes, and few student additions are needed. Studies show that students can either mentally process what you say or write notes; they cannot do both simultaneously (2). The processing is po&tially more efficient for learning. If there is a drawback, it is that students using these notes seem to read less in their texts. Again, with these notes everything presented can be suhjected to careful review. Few other schools use canned lectures. Rod O'Connor used to give canned lectures hy TV a t Arizona (3).At Illinois, a ~
858
Journal of chemical Education
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svstem credited to Gil Haieht has used TV for a decade (4.5). This latter system incorp&ates prerecorded demonstr&ions and experiments into the TV lectures, including having students take dry-lab data. Live demonstrations are now coordinated into class; carts are prepared with materials for TA's to use in the classroom. There are daily lecture notes for TA's. For each day there is a lecture outline, and there are obiectives in a syllabus that students buy for the course. When details are put aside, the Illinois and Nebraska courses have nearly identical features. The biggest difference is that Nebraska uses senior faculty in large classes while Illinois uses TA's in small classes. Unless you known who the teacher is, there is no a priori basis for claiming one approach to be superior t o the other. When you measure student attitudes, and when the course is run a t its best, the canned methods get just as good evaluations as do conventional lectures. The canned methods, however, always cover more ground. Other ARernatlves to the Tradltlonai Lecture Demonstrations and Lecture Experiments Suppose you do not want to become immersed in media, but you do want alternatives t o lecturing. You can start by doing demonstrations and lecture experiments. Because we store visual and auditory memories differently (6),the likelihood that we will recall material is increased via lecture experiments. Also, doing demonstrations gives students a chance to reason out loud and to hear you r'ason out loud, which are among the best ways to cet them to think. In a large room you may need a TV system for image magnification.. Suppose you wish to do a demonstration where students .. . have a chance of predicting in advance what will happenday, boiling hot water using ice, or pouring liquid nitrogen and liquid oxygen over a magnet. Here is a protocol for questioning. First, tell them what you will do. Have them predict the outcome out loud. Then do it. Ohserve the outcome. Finally, have them rationalize the outcome and confront any inappropriate predictions. Demonstrations can be fun for you, but they are also lots of work. (No matter how you do it, good teaching means a lot of work.) Computer Simulations You can also use computer simulations in the lecture, as was illustrated by Tom Lippincott's simulation of a viscosity experiment in the first talk in this symposium. In this area any institution mav have an ind.ividua1that can develoo a "suoer" simulation fo; lecture. We keep a computer in the lecture room, and use it every day to present a student newsletter of class announcements. Teaching Problem Solving Solving prohlems in large groups can also be helpful. Ahout 10 or 20 min of each regular lecture a t Nebraska are devoted to solving problems brought by the students; student participation is expected. The lecture before each hour exam in our course is devoted entirely t o the solving of student-selected problems. When solving these problems I simply reason out loud and write. When we scientists solve problems, we first interpret words (7).Then we try to represent the problem in our minds. We
might substitute some scientific terms such as force or area or pressure in our representation. Finally, we might write down several oossible auantitative relationshins that anolv. When you do problems;n lecture, reason out loud. ~ e ~ i & e ; s often iumo to eauations. Exoerts do not. Instead..exnerts sav t o thems&es things like ' i h , the pressure is changing a; constant temnerature. Therefore the volume will chanee. Therefore thisis a P V problem."Do not just say, "this is a h oroblem." because that is not how vou actuallv reason the problem'for yourself.
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Breaks in Lecture Mary Budd Rowe argues that you get improved performance by having students spend 2 min discussing among themselves what has transaired after everv 10 min of lecture (8).She attributes this to &owing sensory"buffers to unload. Whatever the underlying reason, breaks seem to help performance. Dean Osterman a t Oregon State advocates a structured lecture in which there are 20 min of lecture followed by 10 min in which students work in teams on a particular oroblem (9). This is followed bv another 20 min of lecture. He advocates providing detailed lecture notes for this experience. Formally breaking the class into groups of two or three and having them work on problems, even (especially) in the large class setting, seems to work effectively (10). This aspect of so-called Piagetian learning cycles is often underestimated. Movies Movies are an old standby. I always use the CHEM Study film on "Chemical Families," the Britannica loop on the "Maxwell Boltzmann Distribution," and the La Jolla movie, "Tainted Sky!' Active versus Passive Instruction Keeping students mentally active is the key t o successful teachine. Workine oroblems in class helos. Havine small groups rn class wo;kbn problems helps. ~ a h them-particg i ~ a t ein live lecture exoeriments bv contributine ideas de~ps.
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Alternatives to Large Classrooms
To really be effective, an excellent alternative is t o get out of the room. Three such alternatives include: going to lab, going to a resource center, or giving an exam. The Laboratory Labs should be a great place to work. Regrettably, most large schools have labs run bv TA's who are overly ~ r o u dof th& own ability to recall Ikom long-term memory. TA'S rarely are able u)let students fumble alona and thereby learn to solve problems. Also, most prepared labexperimen& do not allow for much thought. Most teaching labs, particularly in big schools, are over-regimented. In big schools, lab may not be the best place to go. However, labs can be fun and good places to learn. TA's can be trained, but it takes lots of work. In research schools, TA lifetimes of two semesters in a course and two years of total experience are typical. Lab is where the chemistry lecturer has an opportunity that the history lecturer never has, namely, t o meet students as individuals and learn about them. Lab is the place where the good teacher can invest time to overcome some of the shortcomings of the large class setting. I photograph my students
by place in lab, and use photo maps to memorize names. By the end of a semester I aet to know several hundred studentn. perhaps fifty of them quite well. The Resource Center A better place to go than to lab is probablv a resource rwm ( I I ). Our ranned materials are keyed to three help resources: Loebel's prugrammed learning text (12):Hassam Shakhash. iri's taDe suo~lements(13): and PLATO Chemistrv" I (.--, l 4 ) .--In terms bfst&ient utilizkon of the resources we offer, tutors come first: we schedule about 120 tutor hours in the room each week. ~ e xcome t microfiche readers. Students are given microfiche conies of all old course exams with their notes. and they really;se these fiche readers. Third are PLATO &minals, perhaps because of their novelty. Fourth are the videotapes of canned class lectures, which attract foreign students and students who miss lecture for one reason or another. My colleague, Ed Lyons, has made tapes of himself solving assigned problems in the text, and these are rather popular. Magazines, models, audiotapes, videodiscs (an experimental project), and other resources are decreasingly popular, respectively. Exams
Never underestimate giving exams as an alternative t o lecturing. Multiple tries a t exams coupled with rapid feedback is what the Keller Plan is all about (15). Judging from the crowds around our microfiche readers a t exam time, it is clear that this activity as much as any other engages students' attention. Our exams are hand-graded, open-format exams with short problems, fill-in-the-blanks, sentences, paragraphs, and, everv now and aeain. a lone oroblem. Coaies of answer kevs are provided to &dents as'tkey emerge from the exam rwm. Another realitv of the human condition is that more leamine takes place perunit time in those few moments after the e x d than during any other time period.
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Conclusion
One final commentessentially all of the in-class alternatives to traditional lecturing that really work, including problem-solving out loud, require more teacher effort than does traditional lecturing. Good teaching always requires work! Literature Cited (1) Broob, D. W. J. Coil Sci. Troching,aubmittod. (2) Lindsay, P. H., and Norman, D. A.."Human Information P m w i n g , " 2nd ed., Am.
demic P m , New Yoxk, 1977, pp. 346347. (3) Barnard, W. R., and O'Cannor,R.,J. CHEM EDUC., 45,745 (1968). (4) Height, Jr.,G.P., J. CHEM. EDUC.,55,221 (1978). (5) Enger, J., T o m s - W d , A., and Cohn, K., J. C m EDUC.,55,230 (1978). (6) Paiuio, A. "Imagery and Verbal Pmesm,"Lawrence Erlbevm A m i s h , Hilladale, NJ. 1S79. pp. 173-243. (71 Larkia. J. H., and Rsinard,B.,J Rea. Sci. Tach., 21,235 (19%). (8) R o w ,M. B.,J. CHEM. Eouc.,60,954 (1983). (91 ostermann,D. N., . IC d sci. Toochi"& 12.22 (1982). (10) Dab, J. M., "GmupPraessing-AViable Alternativein theCkssidalvcrsusPemndized lmtruetion Contmveray: Summary of Presentations, "Fourth Biennid ConferenceonChemi~lEdumtion."DivisionofCh~midEdumtion, Madiaon, WI,
1976. (12) Laebel, A.B.,ThemicalhblemSolving by DimcmionalAndysi3."mded.,Houghtan Mifnincn Rns+"" IW * . ..... --.,--. .-..,.M..A.,. ..-. (13) ShakhashirkB.2.. Sehreiner.R.. and M e w , P. A.,"WorkbookfmGeneralChcmiatn, (11) Young,J. A,, a n d h g f o r d , C. H., J. CHBM. EDUC.,48,795 (1971).
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