College Teaching / Studies in Methods of Teaching in the College

by Paul Klapper

The laboratory work

The laboratory work should be well correlated with the lectures, especially during the first year. The experiments to be performed by the student should be carefully chosen and should not be a mere repetition of the lecture demonstrations. The laboratory experiments should be both qualitative and quantitative in character. They should on the one hand illustrate the peculiar properties of the substances studied and the typical concomitant changes of chemical action, but on the other hand a sufficient number of quantitative exercises in the laboratory should be introduced to bring home to the student the laws of combining weights and volumes, thus giving him the idea that chemistry is exact and that quantitative relations always obtain when chemical action takes place. At the same time the quantitative exercises lay the basis for the proper comprehension of the laws of combining weights and volumes and the atomic and molecular theories. At least three periods of two consecutive hours each should be spent in the laboratory per week, and the laboratory exercises should be made so interesting and instructive that the student will feel inclined to work in the laboratory at odd times in addition if his program of other studies permits. The laboratory should at all times be, as its name implies, a place where work is done. Order and neatness should always prevail. Apparatus should be kept neat and clean, and in no case should slovenly habits of setting up apparatus be tolerated. The early introduction of a certain amount of quantitative experimentation in the course makes for habits of order and neatness in experimentation and guards against bringing up "sloppy" chemists.

The student's laboratory record

The laboratory notebook should be a neat and accurate record of the work in the laboratory. To this end the entries in the notebook should be made in the laboratory at the time when the experiment is actually being performed. The writing of data on loose scratch paper and then finally writing up the notebook later at home from such sheets is not to be recommended, for while thus the final appearance of the notebook may be improved, it is no longer a first-hand record such as every scientist makes, but rather a transcribed one. The student, in making up such a transcription, is only too apt to draw upon his inner consciousness to make the book appear better; indeed, when he has neglected to transcribe his notes for several days, he is bound to produce anything but a true and accurate record, to say nothing about being put to the temptation to "fake" results which he has either not at all obtained in the laboratory, or has recorded so imperfectly on the scratch paper that he can no longer interpret his record properly. The only true way is to have the notes made directly in the permanently bound notebook at the time when the experiment is actually in progress. The student ought not to take the laboratory notebook home at all without the instructor's knowledge and permission. Each experiment should be entered in the notebook in a brief, businesslike manner. Long-winded, superfluous discussions should be avoided. As a rule, drawings of apparatus in the notes are unnecessary, it being sufficient to indicate that the apparatus was set up according to Figure so-and-so in the laboratory manual or according to the directions given on page so-and-so. The student should be made to feel that the laboratory is the place where careful, purposeful experimentation is to be done, that this is the main object of the laboratory work, and that the notebook is merely a reliable record of what has been accomplished. To this end the data in the notebook should be complete, yet brief and to the point, so that what has been done can be looked up again and that the instructor may know that the experiment has been performed properly, that its purpose was understood by the student, and that he has made correct observations and drawn logical conclusions therefrom. While in each case the notes should indicate the purpose of the experiment, what has actually been done and observed, and the final conclusions, it is on the whole best not to have a general cut-and-dried formula according to which each and every experiment is to be recorded. It is better to encourage a certain degree of individuality in this matter on the part of each student. Notebooks should be corrected by the teacher every week, and the student should be asked to correct all errors which the teacher has indicated. A businesslike atmosphere should prevail in the laboratory at all times, and this should be reflected in the notebooks. Anything that savors of the pedantic is to be strictly avoided. Small blackboards should be conveniently placed in the laboratory so that the instructor may use them in explaining any points that may arise. Usually the same question arises with several members of the class, and a few moments of explanation before the blackboard enable the instructor to clear up the points raised. This not only saves the instructor's time, but it also stimulates interest in the laboratory when explanations are thus given to small groups just when the question is hot.

It is, of course, assumed that the necessary amount of apparatus, chemicals, and other supplies is available, and that the laboratory desks, proper ventilation of the rooms, and safeguards in the case of all experiments fraught with danger have received the necessary painstaking attention on the part of the instructor, who must never for a moment relax in looking after these matters, which it is not the purpose to discuss here. At all times the student should work intelligently and be fully aware of any dangers that are inherent in what he is doing. It need hardly be said that a beginner should not be set at experiments that are specially dangerous. Having been given proper directions, the student should be taught to go ahead with confidence, for working in constant trepidation that an accident may occur often creates a nervous state that brings about the accident. Too much emphasis cannot be laid upon proper, definite laboratory instructions, especially as to kinds and amounts of materials to be used. Such directions as "take a little phosphorus," for example, should be strictly avoided, for the direction as to amount is absolutely indefinite and may in the case where phosphorus or any other dangerous substance is used lead to dire accidents. The student should be given proper and very definite directions, and then he should be taught to follow these absolutely and not use more of the materials than is specified, as the beginner is so apt to do, thus often wasting his time and the reagents as well. Economy and the correct use of all laboratory supplies should be inculcated indirectly all the time. A fixed set of printed rules for the laboratory is generally neither necessary nor desirable when students are properly directed to work intelligently as they go, and good directions are given in the laboratory manual. Thus a spirit of doing intelligently what is right and proper, guarding against accidents, economizing in time and materials of all kinds will soon become dominant in the laboratory and will greatly add to the efficiency of the workers. Minor accidents are almost bound to occur at times in spite of all precautions, and the instructor should be ready to cope with these promptly by means of a properly supplied first-aid kit.

Recitations and quizzes

For students of the first year quizzes or recitations should be held at least twice a week. In these exercises the ground covered in the lectures and laboratory work should be carefully and systematically reviewed. The quiz classes should not be too large. Twenty-five students is the upper limit for a quiz section. The laboratory sections too should not be larger than this, and it is highly desirable that the same instructor conduct both the recitation and the immediate laboratory supervision of the student. Lecture classes can, of course, be very much larger in number. In most colleges the attendance upon classes in chemistry is so large that it is not possible for the professor to deliver the lectures and also personally conduct all of the laboratory work and recitations. It is consequently necessary to divide the class up into small sections for laboratory and quiz purposes. It is highly desirable that the student become well acquainted with his individual instructor in laboratory and quiz work, and therefore it would be unfortunate to have one instructor in the laboratory and still another instructor in the quiz. It might be argued that it is a good thing to have the student become acquainted with a number of instructors, but in the writer's experience such practice results to the disadvantage of the student, and is consequently not to be recommended.

In the recitations the student is to be encouraged to do the talking. He is to be given an opportunity to ask questions as well as to answer the queries put by the teacher. Short written exercises of about ten minutes' duration can be given to advantage in each of these recitations. In this way the entire class writes upon a well-chosen question or solves a numerical chemical problem and thus a great deal of time is saved. The quiz room should be well provided with blackboards which may be used to great advantage in the writing of equations and the solution of chemical problems just as in a class in mathematics. The textbook, from which readings are assigned to the student in connection with the lectures, should contain questions which recapitulate the contents of each chapter. When such questions are not contained in the book, they ought to be provided by the teacher on printed or mimeographed sheets. When properly conducted, the recitation aids greatly in clarifying, arranging and fixing the important points of the course in the mind of the student. Young instructors are apt to make the mistake of doing too much talking in the quiz, instead of encouraging the student to express his views. In these days, when foreign languages and mathematics are more or less on the wane in colleges, the proper study of chemistry, particularly in the well-conducted quiz, will go far toward supplying the mental drill which the older subjects have always afforded.

Summary of first-year course

If the work of the first year has been properly conducted, it will have given the student a general view of the whole field of chemistry, together with a sufficient amount of detail so securely anchored in careful laboratory work and practical experience as to form a basis for either more advanced work in chemical lines or in the pursuance of the vocations already mentioned in which a knowledge of chemistry is basal. It is hardly necessary to add that if well taught, the student will at the end of such a course have a desire for more chemistry.