The CONTRIBUTION of LABORATORY WORK to GENERAL EDUCATION* H. I. SCHLESINGER The University of Chicago, Chicago, Illinois
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URING the past few years, laboratory work for students beginning the study of chemistry and other sciences has been under fire. The attack has come from several sides. School, college, and university administrators, faced with growing enrolment in science courses and with greatly decreased budgets, have been forced to find some way of reducing the per capita cost of education. Smce laboratory work is expensive, its elimination from the programs of many students seems a simple way to effect economies. This motive is undoubtedly responsible for many of the suggestions that individual laboratory exercises be replaced by such methods as lecture demonstrations. But economy is by no m&s the only motive, for the change is seldom recommended as a regrettable but necessary weakening of the cumculum; most supporters of the proposal maintain that nothmg will be lost by the change and many actually claim for i t distinct educational advantages. These arguments are based to some extent on a widespread dissatisfaction with the results of laboratory instruction on the part of teachers. Students, on the other hand, usually look forward to laboratory work with enthusiasm. In the General Course for the Physical Sciences a t The University of Chicago, they often complain that there is no opportunity for individual experiments besides the little provided, as a substitute, by the self-operative demonstrations in the physics museum. All too frequently, however, their enthusiasm wanes when laboratory work is actually encoun* Contribution to the symposium on Lecture Demonstration Method vs. Individual Laboratory Work conducted by the Division of Chemical Education at the eighty-ninth meeting of the American Chemical Society, New York City. April 25, 1935.
tered. In many instances students, who, by their thoughtfully and independently written notebooks, have shown real interest in chemistry develop the habit of doing their experiments mechanically to get the result expected, rather than to observe what is actually going on in their test-tubes. When students nevertheless vote, as they recently. did in my general chemistry classes, for a lengthening of the laboratory period, their action shows an intuitive belief that there should be in laboratory work something which under present couditions they do not get. And, finally, the laboratory has had to meet another major offensive. There is a marked trend toward making the last two years of high school, together with the first two years of college, a period of "general education." Many of the supporters of this movement believe that laboratory work is essentially technical. They would, therefore, eliminate it from the earlier years of a student's training unless he is planning to enter science as a profession or has, a t least, demonstrated special aptitude. Their argument involves two assumptionsfust, that chemistry courses intended to contribute to general education necessarily differ in objective from those planned for the prospective professional student and, second, that laboratory work has value only as a part of technical training. Both of these assumptions demand careful inquiry. All of these problems-that of reducing costs, that of dissatisfaction with the results achieved in the laboratory work, that of the place of the laboratory in a program of general education-I have had to face. In order to my own position in the matter, I decided some time ago to examine the objectives which
have guided the planning of laboratory courses in genera1 chemistry. Although my study of this question has not been exhaustive, I believe that I have gone far enough to justify the selection of the following as the aims of most teachers of high-school and general college chemistry: (1) To illustrate and clarify principles discussed in the classroom, by providing actual contact with materials. (2) To give the student a feeling of the reality of science by an encounter with phenomena which otherwise might be to him no more than words. (3) To make the facts of science easy enough to learn and impressive enough to remember. (4) To give the student some insight into basic scientific laboratory methods, to let him use his hands, and to train him in their use. In the replies to a questionnaire on individual laboratory work versus lecture demonstrations recently sent out from Syracuse University, there is striking evidence that the aims stated really are the motivating objectives in the minds of most teachers of chemistry. Of those who favored the laboratory, by far the largest number said that they did so because laboratory experience fixes facts and principles in the minds of students, increases their interest and enthusiasm, and helps them to obtain a more rapid understanding. Further evidence that these are the major aims of most laboratory courses is found in the number of experiments which the beginning student is usually expected to perf o m a , number so large that it can be understood only on the assumption that the teacher uses the laboratory work primarily to illustrate a large part of the subject matter discussed in the classroom. The common demand that the laboratory manual must follow the order of presentation in the textbook and must contain many questions intended to review and clarify topics discussed in lecture or recitation, indicates that the chief purpose of laboratory exercises is to support classroom work by illustr8tion and example, rather than to attain an independent objective. I have dwelt so long on these purpdljes because I have become convinced that making them the chief aims of our laboratory teaching is the main cause of our problems. Fixing the content of the course in the student's mind, emphasizing the reality of science and the power of the scientificmethod, illustrating principles and giving actual contact with phenomena, are important aims which no laboratory course can afford to neglect. But many teachers question whether these aims cannot be achieved just as effectivelyby lecture or small group demonstrations--or, if not just as effectively, a t least well enough for students who are not preparing for scientific careers. To settle this question many teachers and psychologists are now attempting to measure the relative effectiveness of the two methods. But, so far as I can judge, all of these studies have more or less implicitly assumed the validity of the objectives already discussed. If these, important though they be, are nevertheless not the fundamental aims, such
studies cannot lead to valuable conclusions, and the doubts of many teachers must be resolved by a reexamination of the function of individual laboratory work. In undertaking this inquj., it is best to consider i i ~ sthe t function of laboratory work as a part of general education, and for the moment to leave the student specializing in science out of consideration. In thinking about the latter, it is easy to lose sight of the real duties toward students in the early years of their science training, because the consideration of prerequisites for later courses and the desire to develop specific laboratory technic tend to cloud the more important issue. Limiting in this way the first steps of the inquiry will not result in neglecting the needs of the science major, for it will be found that the fundamental objectives of high-school and first-year college courses are the same, irrespective of the student's purpose in taking them. It will, however, be well to interrupt the discussion in order to consider what is meant by the term "general education." General education is defined in many ways. It is usually assumed to include a certain minimum of factual information about the world in which we live, a t least an acquaintance with the great principles of the natural and social sciences, and an appreciation of trends in philosophy and in art. Though there may be differences concerning the relative importance or even the inclusion of some of these items, everyone agrees that one of the main purposes of general education is to train students in clear thinking. Admitting the importance of this objective, I believe that there are two others of equal significance. In the first place, most of the problems which confront mankind are not such that they cah be solved by logic alone. Almost always, ratiocination must be preceded by accurate observation and a wise choice of premises. The uncertainties always inherent in these processes make it necessary to check the conclusions by further observational tests. Trite as these statements may seem, they are nevertheless of the utmost significance to the present inquiry. Every teacher of elementary science knows that the average human being must learn how to see correctly and observe objectively. The student's powers of observation should no more be expected to develop spontaneously through unguided experience than his knowledge of facts and his ability to think should be allowed to grow by haphazard reading and chance encounters with thought-provoking problems. Teaching students how and what to see is just as much a part of a well-rounded curriculum as is teaching them how to think. Secondly, though observing and thinking may satisfy the academic temperament, most university students do not desire to become either scientists or humanists. Theirs is not to be the contemplative life; they look forward to careers crowded with activity. Education, intended as a preparation for life, has left the guidance of this strong impulse almost entirely to opportunities which the student makes for himself in connection with
the much-scorned student activities. Any scheme of education is seriously defective if it does not include planned training in the art of translating observation and thought into well-considered action. Yet no part of the duty of educators has been so much neglected. In this synthesis of observation, reflection, and action into a pattern of behavior, the laboratory work in the physical sciences is one of the most powerful tools. I say the physical sciences because, although nature studies and experiments with living beings are extremely valuable for training in keen observation, they deal with phenomena so complex that analysis is too much for the beginner. The subject matter of the physical sciences, properly selected, gives ample scope for development of the powers of observation; at the same time it can be made simple enough to allow even the novice to draw definite and valid conclusions. Moreover, properly designed laboratory exercises frequently demand of the student that he check his conclusions by further experiments, not planned or laid out for him, but devised by himself. Thus the labor* tory work can be made to provide training in observation, in thought, and in considered action. As the student learns to check conclusions by tests of his own choice and finds that he more often and more quickly analyzes situations correctly and devises effective experiments, he gains confidence in himself as a reasoning being. The objectives here presented are not thought of as something fundamentally new. They must have guided the pioneers of our sciences when they were training small groups of ardent young men in the famous old European laboratories. But as the number of students with widely diversified interests grew, as it thus became more and more diacult to elicit response to opportunities for individual initiative, as the content of the sciences began to enlarge with astounding rapidity, teachers turned more and more to the illustration of phenomena and to the fixing of facts and principles. The larger purposes were lost to sight. There may be those who will maintain that this picture is not a true one-that instructorsStil1 fully realize the importance of these objectives, but consider them too self-evident to warrant further discussion. If this were actually the case, I am sure no one would suggest, except on the ground of dire economic necessity, that the privilege of taking laboratory work should be limited to especially gifted students or to those intending to specialize in science. Every student promising enough to deserve admission to the last two years of high school and the first two years of college, deserves every possible aid in learning to see, to think, and to act. If these were now the main purposes of laboratory teaching, no one would maintain that there should be a fundamental difference between the laboratory work for a general student and that for a future specialist in science, because the latter, just as much as the former, must learn to observe, to reflect, and to plan a wellconsidered course of investipation before it is worth while to train him in the technic of his specialty. A
course with these fundamental objectives would, furthermore, serve to select from a group of students those qualified for science, far better than does one devoted to illustration of phenomena and fixing of facts, because aptitude in critical observation and ability to devise adequate experiments are more important for the future scientist than ability to remember facts and principles. And I am certain that if the functions I have emphasized were really the chief aims, it would never be supposed that lecture demonstrations can be anything but a poor substitute for individual laboratory exercises. Watching demonstrations gives a student little opportunity to observe anything but that which is pointed out to him, and none to carry into practice any procedure suggested by his own thinking. Having thus rediscovered the fundamental purposes whicb should guide the planning of laboratory courses, let us next turn to means for recapturing the spirit which should dominate a class working toward such objectives. The first step must be to examine the present laboratory exercises in order to determine whether each one definitely benefits the student. If some or even many of them have been included merely in order to illustrate subject matter, or merely to give opportunity to ask leading questions; if they could be replaced just as effectively by lecture demonstrations, let them be ruthlessly cast out. This does not mean that all illustrations of phenomena and principles or all effort to clarify difficult points should be omitted. There are preparations which undoubtedly have value in themselves, e. g., because of their historical interest. But there are other examples, also. Students usually see only solutions of salts of complex ions. If several groups of students each preparqone such salt in solid form and prove to themselves the difference between such compounds and double salts, the result is probably more valuable than the demonstration of a single substance could be. Likewise there are certain phenomena which (as long experience shows) are not fully understood in spite of the most detailed discussion or of repeated demonstration. Such, for instance, is the degree of hydrolysis of salts; a correct impression can be gained only if groups of students roughly determine, with suitably chosen indicators, this value for a considerable series of substances. But it must always be borne in mind that mere illustration of some point or giving the opportunity to asli a searching question is not in itself sufficient justification for inclusion of an experiment in an elementary course. Next, there should be provided exercises the results of which the student cannot readily predetermine by reference to textbook or lecture, because by such experiments, his powers of observation are best stimulated and developed. Again it should be obvious that not all experiments can be ventures into the unknown. The student cannot become an investigator a t once. He must begin with experiments demandmg little more than careful following of directions in order that he mav acauire that minimum of technic without whicb no
