Show-Discuss-Then
Tell
Margaret Henley J. F. Kennedy High School
Los Angeles Unified School District I have taught at threediffercnt high schools in 1.osAngeles for the last iitteen years including a rather highly academic high school, an inner city high school, and a newly integrated high school. Most of my assignments have been in chemistry; honwer. I have also taucht some General Science classes and one ~ntroductionto chemistry. All of the schools had enrollments of a t least 2.500, and one of the schools had enrollment reach 4,M)O in one year: The schools were all grades 10 through 12. The chemistry enrollment in my first school assignment from years 1963 to 1968 was approximately 10 classes of chemistry with three teachers. My second assignment, a n inner city high school which started with an enrollment of five chemistry classes, dropped to an enrollment of two chemistry classes and then increased to an enrollment of six chemistry classes. I attribute the increase in enrollment to a change from curricular materials CHEM Study which required the students to have the ability to use highly formal thought processes, to have a high level reading ability, and t o have avery strong mathematical background. Instead of the CHEM Study curriculum, I changed all hut one of my classes to the IAC curriculum to add relevance and fun to the course. Enrollment moved up immediately from 3 to 5 classes of chemistry. After having taught in twodifferent wgregated schools, one that was Y!&Cauca;ian and one that was 98% Hlack. l moved ro an inteeratrd hirh school feeling that thr Caucasian students wouk benefi6rom contact with Black students and that the Black students needed more competition to motivate them t o work up to their potential. ~ t - t h eschool where I am teaching currently, I have returned to CHEM Study for all but one class, and my 5th class has been designated Liberal Arts Chemistry where I have been using the IAC curriculum.
overhead projector than anything else in the classroom. (In one of the hieh school annuals the students captioned mv picture using the overhead projector as"a shining teacher"). I find the nn~iectorinvaluable tor class discus~ion-I woid lectures-allowing me to have constant eye-contact with the students so that the classroom becomes a discussion "circle" of sorts. By constantly asking questions such as "Why?" "How?" and "What?". I trv to give the students opportunities .. t o formulate their own explanations or hypotheses for many of the phenomena that they encounter. All students are encouraged to participate and they usually do when they lose their fear of being wronn. I tw to take away some of the mystique of chemistry by showing the students that they are able to formulate the same hypotheses that many of the leading chemists did-with a few leading questions, of course. I find the overhead projector invaluable for organizing the lesson material prior to discussion so that the students can keep organized notes. I either print the material myself, usually with a primary typewriter, clr else I use some of thr transparencies that were produced frum the (:HEM Study masters sold bv the 3M Cwnr)anv. . - These are excellent and inexpensive. I have found the most interesting way of producing transparencies is to design them myself since they fit better with my class presentation and I am able to include color and motion in them. For example, when I demonstrate the balance, I use a transparency of the balance beams on which there are movable riders. This allows all 30-35 students a chance to see and to develop skill in reading the balance within 5-10 min. As another example, I find that notched transparent templates representing positive and negatiw ims help the students to develop the process uf writing chemical formulas very quickly. In fact, not only do they visualize the process more quickly, but also they develop an understanding
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Heloino . Students Cooe I am very highly honored to he invited to describe what I have done in teaching as a possible means of helping other secondary chemistry teachers. I believe, however, that any success that I have had with students may be due to my sincere desire to help my students to develop background strong enough to let them cope in Freshman Chemistry and to give them some enjoyment while taking high school chemistry. I cannot claim any definite use of a particular method of pedagogy. Last year a couple of my students, whom I had taken to hear a lecture, described the most impressive thing that they had encountered in my classroom. This was a large garbage bag of helium that I had filled and stored in my stockroom. The students found it "following me" out of the stockroom prior to mv usine i t in a demonstration and a student laboratory expe;imenL I would have been very flattered if they had described the skills that they had developed in problem solving or the concepts in which they had become very proficient; however, I am realistic enough to know that the students interests are primarily with the "action" of the course. I also have found that the action can serve the function of capturing the interest of even the most reluctant students. Therefore, when I reflected on the view of my classroom, the visual aspects first come to my mind. Discussion Circles and Overhead Projection I am probably known by my students more for the use of the
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260 1 Journal of Chemical Education
Margaret Henley received her BS from the University of California at Los Angeles and her MS from Syracuse University. She has taught chemistry and physical science in the Los Angeles Unified School District since 1963. She has sewed as a staff member of the NSF Summer Implementation Program in Chemistry for High School Teachers st Beaver '0 Colleee in 1974and 1975and of the 1 . k Institute at California State University 1975-76. Sewing in several offices for Margaret Henley the California Association of J. F. ~ ~ ~ i school ~~ h n Chemistry Teachers, she also is L~~ Angeles, california a member of the ACS Task Force Steering and Writing Committees for the Preparation of Guidelines for the Premration and Continuine " Educarion of Srrcmdnn School Tearhen. She w a i the rcrlpient of rhr Outrtandmp.Teaching Award hy the lnititutt fur the A d vanemem of Engineering in 19-1 and the 1977 MCA Hrgionnl Award for Excellence in Teaching High School Chemistry. ~
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of the reasons for takine multioles of one ion to combine with another ion. The overhead oroiedor is verv valuable for oroiedine manv demonstrations ifchemical rea&ions that th'st;den&wouli not otherwise be able to see..Most of these I developed from the "TOPS Manual" written by Hubert Alyea except that I found that I could use inexpensive plastic containers bought at stationers'stores and haidware &ores in placeof theceils. I use beakers if the reaction generaws heat. For reactions such as sodium in water or the Tyndall effect using sodium thiosulfate, small amounts of chemicals ran be projected to appear very large and very spectacular. The projecu,r also can he L e d to do wlorimetry measurements such as the I2eSCN I.:quilibrium Constant Experiment with the entire class making the decision on the matrhing to thesundard.Theclass then takes the sinele set of data. and we all work on it toeether. For weakerstudents, doing a very difficult experiment, such as this, as a class exercise takes away the fear that would arise if the students had t o face such a formidable task individually. A Few Mllllpoints of Credit I also use the overhead oroiector to give manv students an opportunity to share theirwork with t i e class without having to stand or write in front of the class. By using blank transparent film, the student can write the w&k on the film which can then be projected for the entire rlass to view. I usually reward the contributor with "a few millipoints" of credit ra value th,tt I determine at the end of the grading period that is fair and eo~iitableto all. I use the term "milliooint" st) that the studentshon2tsimply do this for extra credit;thinking that thereward is not meat. - . but contribute because of ridei in their work). I have found manv other wavs of showing the students chemical phenomena-to discuss:~oys such the Drinking Duck. or the Love Meter serve as excellent devices for senerating interest. T o generate further interest, reactions such as the Luminol reaction, blueprint paper, and hydrogen-oxygen
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bubbles are excellent to demonstrat,e -thermic phenomena, and a dust explosion can leave a lastin impression on the students. I find it almost impossible to discuss molecular behaviol without the use of models constructed from stvrofoam Therefore with the aid of some fine instructors from srvera NSF summer institutes. I have stockoiled a laree number 01 models and 3-dimensionh graphs of &riodic properties of thc elements. A Non-Threaienlng Atmosphere Since my students traditionally have trouble with the for ma1 thought required in chemistry, I find i t useful to havs more than one level in the class. Thus I use the Average-Leve and Above-Average Level designation as was suggested in th, Contract System for CHEM Study which was published i~ Canada. My exams are written in twolevels and several form allowing the students to take "make-up"exams (on their owl time, of course) if they are not successful the first time. Thi; practice appears to lend a non-threatening atmosphere to tht class. Many students will do both levels of the test to insur, the greatest amount of credit. This leads to their performini much more than I exoect them to oerform. I also identifv th, students with outstanding a b i ~ i t y k a in r ~the ~ course and ar range for them to go to the Media Center to view filmstrip, on special topics while I work with the less able students. Thi: keeps the rapid learners constantly working without having to wait for the slower students. Finallv, as I write this. I realize that the most notable thinr about m i classroom is that there is really nothing new abou: the methods that are being used. Rather, it contains an ac cumulation of ideas from teachers all over the country witt whom I have made contact through conferences, institutes or similar programs. Therefore, whenever I give advice to neu or apprentice teachers, I encourage them to participate in suck activities as much as oossihle and to look for eood ideas t c adapt to their classrooms. Any teacher can become a proficienl teacher with that kind of help.
Volume 56, Number 4, April 1979 1 261
