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My Techniques
I have taught first year chemistry for 25 years. This page represents some of the methods, tricks and techniques that I have found useful in teaching and motivating students. I am offering this information free to the educational community. If you desire a copy of this web site with all of the files included on a CD, please send a check for $10.00 to cover the reproduction, handling and shipping cost. Send the check to:
Digital Graphics
7 Roda Drive
Mastic, New York 11950-1709Make the check payable to Digital Graphics ,,,, Thank you - Rich Carman
Chemistry is a particularly difficult subject for some students. It requires them to learn a system of thought, which to them seems imaginary, and a collection of terminology based on this system of thought. Physics (excluding atomic or nuclear physics), at least, is a science in which you can grasp the objects and actually feel the forces you discuss. Chemistry deals with objects and forces beyond direct human detection.
Chemistry depends on faith in the currently accepted theories as a means of explaining the observations. Once this faith is accepted, there is a very large collection of terms and concepts that must be mastered just to be able to speak the language of chemistry. After 25 years of teaching, it is my firm belief that not everyone can grasp a thorough understanding of chemistry. Some individuals will have to settle for a simplistic understanding of the principles of chemistry. I certainly know that there are a number of areas of chemistry which I yearn to understand better.
A "simplistic understanding of chemistry" refers to the ability to visualize or interpret most chemical phenomenae in terms of real world, macroscopic analogies. This would include thinking of molecules as hard little spheres or light as water waves. True chemists realize that these analogies quickly deteriorate under extended scrutiny, but they do provide a degree of understanding. So, there is a pyramid of understanding. Einstein, Planck, Newton Leonardo, etc. were individuals located at the top of the pyramid.
I hope this is not misconstued as "snobbishness" or "conceit". I certainly know my own shortcomings and will quickly admit that there are many concepts in chemistry which I do not thoroughly understand. My placement within the pyramid is hopefully somewhere a little above average. The ability to understand these things is due to a conglomeration of genetic, environmental and educational factors. All I can hope is that there will always be individuals at the top of the pyramid with the ability to pass down understanding and information to the rest of us.I have found that adding an element of competition to the learning of Chemistry actually helped to motivate some the athletically inclined students. I had a stained, shellaqued board which posted the names and high scores. Students enjoyed the recognition for the their achievements and many really got into the competitive side of it. Although many people do not think that memorization should be a part of learning, I think that learning the correct language of chemistry is important to learning and mastering the concepts.
Types of Games
Matching Games - A set of cards was prepared which consisted of paired sets. One card of the pair would have the term on it and the other card would have the definition. These cards would be placed into a large can or other container and shaken to mix. Then the container would be placed upside down on the table so that it was covering the cards. The student would then be timed as the container was removed and the cards were correctly paired up. Students understood that there was some luck involved depending on how the cards fell. However, each student is allowed to try repeatedly for the best time. This kind of game works well with 1) Elements & Symbols, 2) Polyatomic Ions & Formulas, 3) Acids and Base names & Formulas, 4) Organic names and Molecular and/or Structural Formulas, 5) Terms and Definitions and many other sets of information.
Label Placement on Diagrams - A diagram would be constructed on a large piece of oak tag or cardboard. The labels for the items on the diagram would be placed on cards. These cards would be placed in a large container and mixed up. The container would be placed upside down on the table and the student would be timed as he placed the labels on the diagram. This type of game works well with the Heating & Cooling Curve, Reaction Flow Diagrams, Kinetic Energy Diagrams, Electrochemical Cells, Organic Reaction Pathways, Biochemical Pathways and just about any labelled diagram that can be found in a chemistry textbook.
Lab Setup Race - Students are given a table full of lab equipment and must setup the equipment for one or more specific laboratory procedures or determinations. The selection of the lab procedures can be determined through randomly selected cards from a deck with the procedures written on them - one procedure per card. The student would be timed.
Classroom Bingo - Blank bingo cards are made up with 25 squares to the page. I actually make up a master and have the office run off the number of copies needed. The center square on the page is free. The class is provided with a list of terms from the chapter or unit recently covered. Each student is allowed to create thier own Bingo card by filling in one term, formula or symbol in each square. The teacher has already prepared a set of paper slips with the definitions on them, one definition per paper slip. The teacher randomly draws a slipof paper and reads the definition to the class. If a student has the matching term, he places an "X" with a pencil in the corner of that square. Game play continues until someone calls "Bingo!" or "Chemo!". The game can be modified by letting students use a list of terms and definitions from their notebooks... this would encourage good note-taking. This will work with many of the sets of facts in Chemistry.
It has always bothered me that a few students (maybe more) managed to get through the course without actually knowing the required material. They were employing immoral methods to do this. However, proving this can often lead to a heated, noisy confrontation. So, I have spent considerable time and effort in trying to individualize tests, quizzes, classworks and homeworks as much as possible.
Multiple Choice Tests - I would make 2, 3 or 4 different versions of tests. The test could be modified by changing the question order and/or the answer order. Sometimes I would make two tests that were very similar except that the words "increase", "decrease" and "remains the same" were changed within applicable questions. So, one test may ask "What happens to the pressure of a gas at constant temperature when it's volume is decreased?" while the on the other version of the test it would ask "What happens to the pressure of a gas at constant temperature when it's volume is increased?" These tests were so similar that I often had to put subtle clues on them so I could readily distinguish them. These clues would be things like two periods at the end of the test title or something like that. Something noticeable, but not obvious.
Problem Tests - Again I would vary the question order and the numerical amounts used in the problems. The mathematical logic and chemical knowledge needed to solve the problems were identical, however the quantities and units were different. Of course, students always had to show their work.
Matching Tests - Students found my matching evaluations a real challenge... and I can understand why. I would give them a numbered set of phrases and definitions with a short blank line in front of each. The student would put his name at the top of the page. Then I would give each student a numbered lists of terms to match to the information on the first sheet. The student would put his name on this paper also. The instructions were to write the number of the term from page two in front of matching item on page one. If the term was absent from page two or if the definition or phrase was incorrect, place a zero in front of the item. Students really had to know the items cold to do well on this kind of test. Of course, matters were sometimes made worse by having two or three different versions of page one and page two. The two pages were stapled together when they were turned in.
Classwork and Homework - Whenever I assigned homework or classwork which was the same for everyone, all I did was give a checkmark in my book for completion. I would quickly walk around the room and glance at their open notebooks and check it off in my grade book. I told them that as long as they made an honest effort at doing the work I would give them credit. Now these checkmarks contributed a very low percentage to the overall grade, but you had to have them if you wished to qualify for extra credit games or assignments. I would then go over these problems and assignments in detail with the class.
When I wanted to grade homeworks and classwork, I would resort to individualized assignments. Originally I generated these assignments with a set of programs I had written on an old Atari-800 computer. Later I switched to the same programs rewritten in Quick Basic. Essentially the programs would pick a type of question and then fill in random quantities and generate an answer an answer key for all of the sets at the end.
This can now be done in somewhat similar manner with a simple spreadsheet such as Quattro Pro, ClarisWorks or Excel. Create a table of values labelling the columns with things like Q1-V1 which would stand for Question 1 - Value 1. Print out the table of values and distribute one to each student. Write the problem sets in a general manner with the terms Value 1, Value 2, etc. where the numbers would normally go. Tell the student to solve the problems using the values assigned to him from the distributed table.
The answer key can be generated for grading purposes from the spreadsheet just by putting in the appropriate formulas. One of my projects is to rewrite my programs in Visual Basic or C++ one of these days. If I do, I'll post the availability of them on this website.I have no qualms in letting students do additional work in order to raise their grades. However, I do not let them do extra credit work to pass the course. Only a student with a passing average may do extra credit work. Even so, the student must meet the following criteria: 1) Good attendance, 2) No missing checked work (Homeworks and Classworks), 3) No failing test grades, and 4) No missing graded work. Such a student was deemed "in good standing" and was permitted to do extra credit work. This extra credit work can take the form of Extra Credit Games, Typed Reports, Oral Classroom Reports, Charts & Diagrams for the wall displays, and even tutoring their fellow students. Students could also retake tests on topics and have the second test grade averaged with the first to get a new test grade.
Students with failing averages could raise their grades to passing by taking further evaluations. If a student got a 60% on a test, they could take a retest. If they passed the second test, they would receive the minimum passing grade for the test (70% at my school). The make-up work would have to be done during their free time (study hall, recess, before classes or after classes).