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a& 8th N e w England Association of Chem
Jesse H. Day
Ohio University Athens
Programmed hstruction in Chemistry O n l y the students have no gears
Chemistry teachers will shortly be offered an assortment of "teaching machine programs" and "programmed texthooks" from a variety of sources, including the Encyclopedia Britannica, the Center for Programmed Learning, the G~olierCo., Rheem Califone, and most textbook publishers including Doubleday; McGraw-Hill; Harcourt, Brace; World, Allyn and Bacon; and doubtless others. There has been tremendons activity and interest in programmed learning in academic circles and among psychologists, and especially in the various armed services, in industry, and in management (the recent meeting of the American Management Association on this subject lasted a full day). The basic idea of programmed instruction is valuable, and has been given very substantial support by the Ford and Carnegie Foundations and others. Much of the excitement, however, has been premature, and it will be a testimony to the survival power of a good idea if the whole movement does not evaporate in a mist of heady talk. The only chemistry programs actually available at present are still fragmentary. The most substantial to date are those of Young1 and some short programs by the a u t h o ~ . A ~ suggested plan for programmed chemistry instruction was also presented at the Fall 1961 ACS meeting by Paul Carnell. The whole issue may well seem both cloudy and amorphous; the brain children of the early workers, Skinner, Holland, Crowder, Mager, and others, find themselves with an oddly assorted group of vigorous and well-meaning god-parents including big-E educationists, manufacturers of machines, and publishers of texthooks. The Promise of Programmed Learning
When a student is studying a teaching machine program: He cannot proceed from item 1 to item 2 until he has learned
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Journal of Chemicol Education
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item 1. Thus there is a built-in guarantee that when he has finished the program he has learned oll ot it, not just the 90% needed for an A. He is continuously active. He cannot skim or star-gaze; the program naitspatiently-thestudent must makeactiveeffort. The student learns rhat he does; he is no passivesponge. He proceeds at his own pace; the bright go quickly, the notso-bright moreslowly. The well-written program is 60 logical, clear, and consecutive that the student rarely fails to make each step. It is not like a turgid textbook u-hose explanations need explanations. The student receives immediate confirmation of each right answer, or immediate correction if v-rang. There is no waiting while papers art? graded, the question forgotten, and interest past. The confirmation of correctness at each step is tremendously encouraging to the student and provides confidence for the nextstep.
The promise of programmed learning thenis the promise that here is a wav to vresent material that the student mill actually learn-and enjoy as he learns. The promise is that the teacher can start a lecture with more than usual confidence that the background is understood. The promise is that the student can learn more by himself, leaving the teacher free for the creative demands that mark the good teacher'^ most effective use of time.
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Where Are the Machines?
There are more kinds of machines than there are programs. Machines apparently are not absolutely necessary, though they do offer advantages: the machine can prevent cheating, can present a record or score of successes and failures and so spot bad items in the program, and can sit in a corner of the room for consultation whenever desired by a student. The variety of machincs is great, and they range in cost from about 20 to many thousands of dollars. Their disadvantage is that the student cannot take one home with him. But one can foresee a possibility in this: a sort of washateria or supermarket, located next to a college campus with a dozen or so machines in it, where the student can go in, choose the program for balancing redox equations, put in his quarter, and go to work. The program is the important thing, and the manner
Writing Ihe Linear Program
Whal to Do Choose n limited topic; preferably one your stndcnts have trouble with, or that you spend time helping them with. Define precisel?, what you r a n t the program to teach. Do not be g e n ~ r a lhere or has?; n u k e your specification precise and complete. Decide on your approarh and stick with it (don't confuse the issue!). Is the f i n t s e p to ire (a) find the number of moles of given.. . ur ( h i find the ratio of weights of given or ( d l and unknovn. or ( r ) this is to this as t h a t . . some othrr approach. Deride on the- beginning or introduction.
For Eza,nple (The Programmer Talks to Himeelf) Problemsolving! Given a balanced chemical equation, all molecular weights, and the weight of one substance, calculate the needed or resultant m-eight of any other substancein the equation.
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Outlinp the diwetion and dcvelapment you a n n t the progmm to takc.
How about beginning with familiar cases, such as the cost of doughnuts, which deals with a unit (dozen), similar t o the mole. (Avogadro's number.) A dozen is a familiar unit. Cost of 17 doughnuts at $ 3 7 a. dozen. Number of doughnuts that might be bought for 50.20. Cost of 1gram of CuSO,if 1mole ( g r a m s ) cost-. Other examples as above, to lead to the rule, "to find number of moles in a given weight, divide given m i g h t by weight of one mole!' (units!) ( a t c e n t s a Now, to trade $3.50 of CuSO, for gram) estsblish "equal values" so trading can be carried on without money. Xow forget money, and deal in "equivalent amounts." (Is money trick worth while? Or better left out?) Examples, leading to final rule, "divide givm weight by molecular weight and multiply by the molecular weight of the unknown to get grams of unknown!' Extend examples toinclude cases where male ratio is not 1to 1. Take a stack of 3 in. X 5 in. cards, numbered ronseeutively. Write on first card "Doughnuts cost $0.57 a down. T~venty doughnuts would cost (On second thought, let's make the fint step easier, also reasonable. Eighteen doughnuts is dorm, and $0.58 is divisible by 2!) Therefore "Doughnuts would cost .58 per dozen; 18 doughnuts would cost Now write on the back of the card, 18/12 X 58 = 87. And so on. "This program nil1 help you work . . ." "l-ou nerd to know before you start: how to find molecular reighte, what the weight of a. mole is
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Write a short introduction.
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Give the complet,ed set to onestudent to work through. Thcrevcr he makes an error, try to revise that card, or add others, to make sure the next student won't miss. Listen to the student's connuents (if any). And remember that you are on his side; 1-ou are not testing him, you are testingyaur o m program. Repeat step 8, using different students, until you find a t lcsst tm oonsecutive students who get all the way through without difficulty (note without difficulty, not without work!) Prepare the program for the class; then on the hasis of thcse results, continue to revise, dropping out unnecessary i t m s or adding as needed. Provide at least 10 or 20 drill problems, to& the idea or process.
of prcscntation murh less so. The best way to discover what a good program is, is to write one, and try it out. If you do this I promise fnn and a few surprises, and then when the promised programs are available to you, you mill he in a much better position to judge whether they are worth trying. The statement is common that no one can teach how to write a program, but perhaps this is not strictly true since we do have teachers of writing and of painting. There are presently only two general t,ypes of programs, the linear and the intrinsic. In preparing the program for class use it may be inconvenient to use 3 in. X 5 in. cards, especially as some might become lost or disordered. Here are some rays, and your ingenuity will suggest others: mimeograph four frames to a sheet of paper (or five, using legal size), cut the frames apart and staple them on the left edge, giving a booklet 8'/2 in. wide and a little less than 3 in. high. A second may is to mimeograph the program entirely
on full size paper in this fashion: frame 1 at top of page 1, frame 2 at top of page 2-let us say t,he program consists of 48 frames, and that you can get 8 frames on a sheet-the 6th frame would go a t t,he top of page 6, and the 7th frame would go on page 1,just under fl.ame 1, and so to the end. In this format, the answer to each frame can be put in a separate box or spare on the following page, just to the left of the next question frame. Still a third way is to place the frames consecutively down the paper, with the answer to each frame printed just below it in the right hand margin. The student would cover the work sheet with a piece of paper or cardboard, make his response, then uncover t,he ansver by sliding the paper down the work sheet. The same vork sheet would also fit a file folder nrhich has t ~ o windows cut into it; the student would slide the m r k sheet upward for each new frame. Still anot,her \Yay is described by Young.' Programs may be saved for re-use by having the Volume 39, Number
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student write his responses on a separate sheet or roll of paper. Writing the Intrinsic Program
The intrinsic program differs from t.he linear program in that each ouestion (instead of leadine to one roba able correct answer) suggests at least two alternatives, and each alternative has a page reference. If he chooses an incorrect answer, the page he is referred to tells the student why his answer is incorrect and leads him through intermediate reasoning st.eps before going to ailother question. If he chooses the correct answer, the page he is referred to tells him he is correct and perhaps explains further, then asks the question which carries the student up the next step in the learning process. The intrinsic program is harder to write well, but has some advantages that make it worth the effort in some types of snbject matter. Though it has the possible disadvantage of suggesting wrong answers, it has the very real advantage of being able to correct common ermrs or misconcaptions that seem bound to arisr. Further, it is less apt to become boring for the student and it can be written in a very informal and personal st,yle, simulating a friendly tutor. The disadvantagr of suggesting wrong answers can be minimized by including only answers a t which (experience has shown) students often arrive in studying the suhjmt. As in the linear program, it is necessary to choose a limited topic, define precisely what you want to teach, decide on your approach and stick with it, and work in small, logical steps. Let us take as an example a f e v frames of a program on the kinetic theory of gases.?
PAGE 26 Your snsner was, "Even a gns has might, and weight exerts pressure." The problem stated that a gas in a closed container exerts p r w u r e equally in all directions. This means that oressure is exerted uou-ard as u-ell as
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PAGE 17 I t has been found that any gas confined in s closed container exerb n real pressure against the inside of the container. The force is exerted equally in all directions. How does the gas exert this pressure? (In what manner? Ry what mechanism? What is going on?) Even a gas has weight, and m i g h t exerts pressure. a. (Page2G.I b. Since the moleeules are each surrounded by their electrons, the electrons repel each other and shove the molecules apart. (Page 6.) e. The molecules me in motion, and when they bump the inside of the cantsinor the force of the bump pra-es outward. (Page52.)
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Journol of Chemical Education
PAGE 6 Your answer was, "Since the molecdes are each surrounded by their electrons, the electrons repel each other and shove the molecules apart." 1-oo are overlooking the combined gas l m s ; d o n l h g the amount of gas in the same container \\ill dool,le the pressure. Electric repulsion functions inversely as the square of the distance between charges. Ihubling the numhcr of molecules would incrcnse the pressure to four ti~nesits initial value if electrostz~ticrq,ulsion were the cause of the outward pressure. Sam go h:lck to psxe 17 for another try. PAGE 62
Y m ~ rs,nsa.Fr was. "The molecules arc in n~ction. -. ~~~
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YOU ARE CORRECT. And since the pressure is r s r r t d cqnally in :dl directions. the motion must be random. Now since the molecules are moving a t rendom, the?must collide with each other as n-ell as with the vxlls of t h r cantitiner. I t is common experience that there are frictional losses of energy when two moving objects touch. What would happen if there were any frictional loss of energ" on collision between molecules? a. The pressurein the container of gas \\nntld constantly grow smaller. (page 12) b. Nothing would happen. (page5) c. The friction ~ o u l dresult in heat and the temperature would pa UD. (page 113)
For further information the interested reader should first read "Teaching Machines and Programmed Learning," by Lumsdaine, A. A,, and Glaser, R., published at $7.50 by thc National Educa.tion Association, Washington, D. C. This book is romplet,e and comprehensive. Sources of informa%ion on currrat m r k include The Automated Teaching Bulletin, free quarterly, published by Rheem Califone, 1020 S. LaRrea Avenue, Los Angeles; the publicat,ions of the Center for Programmed Instruction, Inc., 365 West End Avenue, New York 24, Xerv York; and A.I.D., puhlished at $0.50 a copy by A.I.D., P.O. Box 44.56, Lubbock, Texas. The excellent article by Young1 will give fn~T~hcr insight into program writing.
