Jesse H. Day
Ohio University Athens, Ohio
Intrinsic Programs
O n e perfect way to learn would be to read a textbook that was clearly written, so logical and complete, that one could not fail to understand. This textbook has unfortunately not yet been written. In simple fact, most people cannot do a very good job of learning from most hooks. The reasons are numerous but fairly simple: first, each text assumes that a certain background is possessed by the reader, but without specifying that background in other than a general way. For example, a problem on the osmotic pressure of blood that does not specify the solvent just might frustrate a student with no biology background. Another trouble is that books are generally written for the teacher, not for the student, and the teacher must fill in the missing pieces for the student. But if a single point is left out or slurred over, the beginning student may well he lost, so that the whole topic is a source of confusion. Most books are guilty to some degree. There are other troubles. The student does not always read well and accurately, and sometimes he only skims. He is usually unable to separate the major ideas from the incidental description, and he almost never stops to work out each idea as it appears and make it his own. If only the student could he kept on one idea a t a time until he mastered it, then half-mastery would not plague his further progress. If only the interested, working student could ask the crucial question a t the precise time he needs the answer, and if only the student could know whether he is on the right track as he goes, most of these defects would disappear. Proeramed instruction is the one amroach to learning that makes an honest and total effortto correct all the troubles mentioned above. I t is first judged successful in terms of student success, not in terms of teacher evaluation. It forces the student to learn every single point, one a t a time, and to make it his own property through his own activity. It can correct him when he gets off the track, and reassure him at every step he takes that is right. When the student has gone through a well-written program, there is no need to ask whether he has learned or understood the material. Unfortunately, programs have their drawbacks too. They can easily become boring or tedious or both. They are prodigal of space, time and paper. But they can have two very greatly beneficial effects. The first, and maybe even the most important, is in teacher improvement. The teacher who conscientiously writes a program-no matter what kind or how smallon a topic that gives the students trouble will find possiPresented at the Symposium an Programed Instruction at the 124th Meeting of the American Chemical Society, Atlantic City, New Jersey, September, 1962.
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Journal of Chemiml Education
bly to his bewilderment and certainly to his enlightenment, just exactly how much prior knowledge is expected of the student. He will also find that the small, simple concept he started out to explain is fraught with perilous assumptions which we have long since learned to swallow, that are very hard indeed to swallow the first time. The experience then of revising, based on student error and difficulty, adds a chastening sense of modesty to the teacher's confidence in his ability to explain. And a t the end, the teacher has learned a new appreciation, not only of his subject, hut of the importance of his own task. He cannot fail to be a better teacher for the experience. Dr. Young has stressed this in his remarks.' The second beneficial effect of programed instruction is its great usefulness for the student. Probably in chemistry the best place for programs is as small individual units, designed to teach a single concept. They can be, and should be, used together with every other resource the teacher has-lectures, tutoring, TV, movies, film strips, demonstrations, laboratory, homework, and if possible, discussion. Programs may best he used to carry the small fortresses of difficulty that are perennial holdouts; how to solve weight-balance problems, how to balance redox equations, and so on. The programs can be used either to introduce the suhject, or to supplement or replace the textbook on that subject. The validity and success of programs have now been well established, especially in the armed services, and in the whole world of industry, including such management functions as decision making. The Intrinsic Program
The intrinsic program differs substantially from the linear program.' The figures taken from an intrinsic program dealing with the kinetic molecular theory will illustrate this. Notice that first the target population is defined (Figure 1 ) . Anyone who has finished a t least part of a course in high school chemistry and physics should have no trouble; we are aiming primarily a t the college freshman and the physical chemistry student. The objectives of the program (Figure 2) are carefully spelled out, so the student knows what it is he will be able to do when he has finished. Xotice also that the background knowledge required is completely and exactly specified, so the reader will know whether he is ready for the program or not. In all three instances programed instruction is sharply distinguished from the textbook and other forms of learning materials. See Preceding paper in This Symposium, THIS JOURNAL, 40, 11(1963).
page 20 Your answer was, "If the molecules are not round. then some energy may go just to spinning the molecule around." You are correct. I t is oossible for two molecules to collide dead center. b'ut since collisions will be a t random, most will strike not in the center. An off-center hit will spin the molecule; just as when you throw a baseball bat, the bat spins and flies throueh the air simultaneouslv. So. with molecules whi& are not spherically ~ymme&cal, some of the kinetic energy is rotational as well as translational. I t is still kinetic energy, and may be passed on in the next collision as a new distribution of rotation and translation, just depending on what part of one molecule hits what part of the other molecule. T o see how this works, put a pencil on the table and strike i t near the end. Notice that the pencil turns as i t moves. Turn to page 17.
IS THIS PROGRAM FOR YOU? This program is designed for the reader who has completed a t least a high school course in Chemistry or Physics. I t will be most useful to students in General Chemistry and in Physical Chemistry. p~~
Figure 1.
PREREQUISITES I t is assumed that you know or are familiar with the following:
1. That a molecule is the smallest particle of a compound; for example, that O1 is a molecule of oxygen. 2. That all molecules of a pure substance are identical (ignoring isotopes for now). 3. That an "atmosphere" is a unit of pressure, sufficient to support a column of mercury 760 mm in height. This is about 14.7 1 b / h P . 4. That a "liter'' is a unit of volume. It is a little larger than a quart. 5. That the equation for a straight line has the form
Figure 5.
y = a z + b
where a and b are constants. Figure 2.
Your answer was, "Exactly 25 lb/in.P." You are correct. If the container is not distorted or the temperature changed, the pressure will remain constant f6rever if the container is absolutely air-tight. But the molecules hit the wall. and certainlv thev must collide with each other freakentlv. If we know the pressure remains constant over trme in a sealed container, and if we know the moving molecules are hitting the wall and colliding with each other, what n sa result of can vou conclude about what h a.~ . ~ e as the& collisions? Page 17 (1)that of two molecules colliding, together they have exactly as much kinetic energy as before. Page 18 (2) everybody knows that when two objects meet there is friction, so the colliding molecules will have less energy after colliding than before. Page 19 (3) since some collisions will be head-on and some sideswi~es.then some molecules will wu
to spinning the molecules around. Figure 3.
I
Your answer was, "Everybody knows that when two objects meet there is friction, so the colliding molecules will have less enerev -- after colliding- than before." Follow the line of reasoning to its conclusion and see where i t ends. If energy is lost on collision, then after a while there would be no enerev left. And no energy of movement means no pr&ure would be exerted. No pressure is zero pressureand this is aperfect uacuvm! I t just does not happen. But i t would happen if anv enerrrv were last on collision. Since this does no; happ&, then no energy is lost on collision. In other wards, the molecules are 100% elastic! Now turn to page 17.
Figure 4.
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At the end of the program there is a short objective test, so the student can find whether he has mastered the material in the program or not. If there is an error or uncertainty, the correct answers given on the next page also direct him to the page in the program where the point is discussed for whatever review or clarification is necessary. Again, this attitude is unique to programs; the reader a t the end knows exactly how well he has mastered the material; and if there is something missed, he knows exactly where to go to remedy the defect. Now consider a few frames from near the end of Part I of the Kinetic Theory of Gases which my students have used for the past few years (see Figures 3,4, and 5). First, the question is repeated, and confirmation of correctness given, then confirmation of the reasoning that must have been involved (or a t least the reasoning that would correctly lead to this page). Then a further question is asked about one detailed aspect of the picture the reader has by now drawn. He is steered to think about a question that will be fruitful. Notice that of the four answers presented for choice, three are correct, and the fourth is certainly reasonahle and not so novel or shocking that it will be remembered. To see what happens if the one wrong choice is made, note'Figure 4. If the student chooses page 20, he will be confronted with Figure 5. Then he is led to look at the other correct answers. I n other words, he sees all the three correct answers, but has chosen the order in which he will see them. The correct answers eventually all lead to the next subject, and so on. The concept presented on a single frame is not necessarily a single nor a simple concept, but it is a unit, a single piece, which the student must absorb before proceeding. The objection that it is bad pedagogy to suggest wrong answers does not necessarily have great validity if all possible choices are presented with real purpose. In any event, the multiple choice test question is here to stay, and students are familiar with them. Students are test-wise and not easily led astray by even a formidable array of wild choices, no matter how novel or interesting. The intrinsic program has the advantages of providing various sized steps and correction for errors; it is Volume
40,
Number 1 , January 1963
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less boring, and probably more acceptable to the better students, while less well adauted to the uoorer. Programs are appearing on the market, and every teacher must not only decide whether he will use them, but also learn how to recognize and separate the good ones from the bad. I also concur heartily with the opinions already expressed that a sure way to become
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Journol of Chemical Educotion
a better teacher is to try conscientiously to write a uropram. . General -. ..-.-. ... .. .. .....
CRAM,D., "Explaining Teaching Machines and Programming," Fearan Publishers, San Francisco 1961. MAC,, , R . '~premrinc Ohiwtiv~s for Proerammed ~nstruetion. ~"~~~ Fesron Publishers, San Francisco 1961. -
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