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view from my clamoom
edited bv FRANK CARDULLA Niles Township High School 9800 Lawler Avenue Skakie, IL 60077
Maximizing Student Involvement in Learning Pat Noel Westlake Schwl, 700 N. Faring Road, Los Angeles, CA 90077 Each fall before school begins, I consider the challenge of focusing students' interest on chemistry. Most students are enrolled in chemistry to fulfill a prerequisite for college. Students are under a great deal of pressure to succeed, and chemistry often apears as a roadblock to that success for the average student. T o generate interest and understanding in the course, I incorporate a variety of techniques including laboratory experiments, mini-labs, demonstrations, and discussions. The goal is to have students thinking for the entire class period. This happens when they are actively involved in the learning process. In addition to formal laboratory experiments, some of the techniques that help to achieve this goal are described below. Toy ol the Week Puzzle (1) A tov to the class a t the beeinnine of each - is presented . week and remains on the demonstration table for investigation. Bv the end of the week. studentsdevelon hvoothesesas to how-the toy works. For example, after dk;ssing vapor pressure, the "Drinking Bird" is introduced to the class. Students are asked to ol;serve its behavior and to determine how it works. The toy is a stimulus to increaseobservational skills, encourage discussion, review concepts, and stimulate cooperative learning. Students are fascinated with the toys and invest time solving the puzzle without earning credit. At the end of the week, we collect the ideas and either arrive a t
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Pal No01 currently teaches chem isby and advanced placement c h e m ikby at Westlake School f w Girls in ; Los Angeles. CA. Fifteen of her 19 .,' years of teachlng have been in Los Angeles area public high schwls where her assignments involved physical SCIBIICB. earth science. consumer science. ohvsics. and coachmg varsoty soccer n sdanmn to teacnmg cherntsby Noel earned her BA at lmmaculam Collepe In Pennsylvania and her MA at Claremont Graduate School in California. Since 1983 Noel has been Involved In the development of me ACS "Doing Chemistry" videodisc program as well as cmducting workshops for teachers of chemlsby. Some of the awards she has receivedare: Western Regional Catalyst Award. 1989;Research CorporatlonQant. 1988. 1989;HopeCollegeFellowship.1988:Wwdrow Wilson Foundation Fellowship. 1986, 1989. Nael has been a member of the Environmental Chemistry Woodrow Wilson Traveling Team since the summer of 1990. In addlmn to teaching chemistry, she a i m enjoys photography. hiking, golf. and birdwatching.
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1004
Journal of Chemical Education
an explanation or devise experiments to test some of the hypotheses suggested. Two-Mlnute Qulckle Demos Short demonstrations to illustrate a principle during lectures are an integral part of my classroom technique. As many as four or five brief demonstrations per lecture are used. During the introductory discussion of the properties of matter, I prepare each of the following mixtures and have students observe and describe the properties: homogeneous mixture (sugar and water); heterogenoeus mixture (oil and water): suspension: (clav and water): colloid: (Jell-0 and water, show Tyndall effect); solution: '(salt and water, show no Tyndall effect). I t is easy to illustrate separation techniques for these mixtures. The oil and water are placed in a separatory funnel, shaken, and allowed to settle. Then the water is removed from the oil. The clay and water mixture is filtered, and the salt water solution is distilled. The techniques described in the text now have more meaning for the students. Student Demonstratlons Student teams of two or three prepare demonstrations and present them to the class during the discussion of a topic. Student preparation includes settine- un. eauinment .. aid materials, braiticing the demo in front of an audience, and developing a handout for the class. An area of chemistrv that worksweil with this approach is gas laws. T o introduce the effect of air pressure, one group of students may demonstrate a collapsing soft drink can, the balloonin the bottle, or the egg in the hottle. The demonstrators introduce their experiment, ask the class for predictions, perform the experiment, solicit hypotheses from the class, and hand out a printed explanation of the demonstration. Another group may illustrate how air pressure ismeasured using a manometer and discuss the units for air nressure. I t has been mv observation that the topics students demonstrate are those thev remember best. Each student demonstration receives themme credit as a laboratory report. Demonstratlons a s Test Questlons Each unit test contains a demonstration question. I perform a demo, and the students must record the setup, procedure, observations and construct a hwothesis to exnlain what they have observed. A great impkvement in observation and analvsis skills occurs during the vear. A favorite demo test involves d e n s i t y . ~ ~ o ~ 2 5 0 Erlen-ml meyer flasks are prepared. Two of the flasks contain hot water colored with red food dye, and the other two flasks contain cold water colored with blue food dye. The flask with blue food dye is inverted over one of the flasks with red food dye. Observations are made. The flask with red food dye is inverted over the flask with blue food dye. Again observa-
tions are.made. The flasks remain in front of the students .-.-~~ until the end of theperiod. Students observe that when the flask with blue food dye is inverted over the flask with red food dye, the colors mix. However, when the flask with red food dye is inverted over the flask with blue food dye,there is no mixing of colors. It they understand the concept of density, they will be able to hypothesize that the cool water (blue food dye) is more dense than the warm water (red food dye). When the more dense liquid is inverted over the less dense liquid, it displaces the less dense liquid and the colors mix. When the less dense liquid is inverted over the more dense liquid, the liquids do not mix. Students usually feel uncomfortable about this type of test question at the beginning of the year. In order to allay their fears about grades, I break the question into parts and weight each part equally. For example, students would receive equal credits for accurately describing the setup and procedure, making observations, and constructing a hypothesis. ~~
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Demonstrations as a Revlew Technique
During the review period before final examinations, each student feam is ask& to select an area of chemistry they found difficult during the year. They are given a demonstration to prepare in that area. At the review session, the students present and explain their demonstration to the class. From student feedback this activity aooears to he quite helpful as a review tool. These demo&;aiions will cover all tooics for the vear and the challenge is finding an avorooria& activity f i r each topic. some good soukes f& these demos are: Summerlin (2,3), Shakhashiri (4),and Dreyfusl Woodrow Wilson Modules (5).It is very important for these demos to be teacher-tested before assigning them to students, as not all demos work as described. Students receive laboratory report credit for their presentations.
System" lab in Chemtrek (6) for my first-year chemistry students. When they arrived in class on the first day, they were eiven a handout that led them through the exoeriment by h a h g them make observations and answer quekons. By the end of the oeriod. thev were asked to make a hwothesis as to how " ~ 6 e~ y s k m "(also known as the BIGBottle) worked and to devise ex~erimentsto test their hmotheses the next day. As the students arrive the next dai,they are eager to try their ex~eriments.This is exciting because there are a variety of tests being performed at each lab station. During the class discussion, each group arrives at a similar conclusion, but no two groups perform exactly the same tests. By the end of the second day, these students are eonvinced they are doing science, and they are! It is a wonderful way to begin the year. Overhead Transparency Handouts
Students are given copies of all overhead tranparencies that I plan to use during a discussion. This allows them to focus on the topic instead of copying what they see on the screen, and they can use the overhead handouts for notetaking. As school ends, I analyze the progress toward achieving the goal of involving students in learning for the entire period every day. The activities described above have helped, but complete student involvement in problem solving requires having them spend more time doing experiments and analyzing the results. Students who are actively involved in learning on a daily basis tend to have a greater interest and understanding of chemistry. Each year a few more student lab or demo activities are added to my course, and I inch closer to this goal. Literature CMed
Minl-Labs (In Place of Teacher Demonslratlons)
Adantine demonstrations to microscale lab activities allows siudeka to be more involved in the thinking processes required to solve a problem. This is usually more time consuming than a demo, but the student benefits are great. I tried this as a first day activity using an adaptation of "The
3. Summerlin, LeeR.;Borgford. Ch&iie:E&, Julie ChemicolDemowtrnlions:A Sourcobook for Toochem, Volume$ ArnerieanChernic.4 Society: Waahinglon, DC, 1987. 4. Shakharhiri. Baawm 2. ChemicolDomowfrofionr:AHandbook for TeaehwaofChmIstry: ~ n i h r s i & a f~ i a c o n s i n Madison. : WI. 1981,1985,1986~~ob. 1and 2 ' 5. DmvfuaiWmdrow Wilson Modules. 1982-1989. Wwdrow W i b n National FeUovshio ~ k d ~ tP.i0.~Box~ 642. , Prinnton, NJ 08540. 6. Thompson. Stephen. Chemtrek.Allyn end Bacon: Bastan,MA, 1990;pp 1-9. ~
Volume 67
Number 12 December 1990
1005
