Grouping Students for Work in the Chemical Laboratory W. G. BOWERS, HEAD CHEMISTRY DEPARTMENT T HE problem of grouping students for laboratory work, especially in sciences which require expensive apparatus, has been in the mind of the writer for several years; largely perhaps, because his experience has been, for the most part, in teacher training institutions. Two conditions. prevail in the teacher training institutions which may be responsible for this: First, the instructors in such institutions have uppermost in their minds problems concerning methods of teaching, under which condition the primary interest would be as to whether the student could learn more from his laboratory work, by working alone or with a partner. Second, in such institutions it is generally more difficult to supply the student individually than it is in technical schools and other kinds of schools. We have been unable to find that any one else has ever collected data on this problem. Teachers in the field must have made considerable observation, but as to collecting data, such would of necessity offer many difficulties. We have been making observations in our own laboratories for fourteen years. The first eight years of this time we collected data. We finally concluded that we could get nowhere with loose observations excepting to allow them to enter into our methods of making up grades for the students observed. We felt safe then in using these grades (providing we considered large numbers of them) from which to draw conclusions. However, these observations were not all upon which we depended in making the grades. We had numerous oral quizzes, frequent written tests, and many laboratory questions in our semi-quarterly and quarterly examinations. Also we carefully grade notebooks. In our eight years of observation in which we collected no data, as well as the six years during which we collected data, we noted many conditions which distracted from or aided in furnishing most favorable circumstances for obtaining best educational results from the students' laboratory work. In the following discussion we are aiming to make an unbiased presentation of these conditions before we give our tabulated data. This will perhaps aid in the interpretation of the data and the explanation of the conclusions. These conditions may be taken as advantages or disadvantages for the different groupings. In our casual observations we noted some conditions as follows: Two people working together talk with each other about their work. If they are working at the same experiment they are not so apt to talk about something other than their work as they are if they are working independently but close by each other. If they are doing the same exercise their interests are common. They exchange ideas and stimulate each other. If they are working independently they are liable to be working on different exercises or at different places in the same exercise. They will not have common interest as far as work is concerned and will most likely converse on something foreign to the subject. The student who says he can think better when alone perhaps remembers only antagonizing influences. The student who says he can think better in the absence of the teacher perhaps has a teacher whose presence embarrasses him. In most cases students take up the day's work with more courage and confidence if they have companions. This means a great deal to beginners, for in many cases the discouragement disenables the student to think sufficiently to start on a piece of work which would be easily completed if he had only the slightest bit of help on the start. Such a student will remain perfectly helpless until the instructor helps him with the first step. Under ordinary conditions the first step would be all that would be necessary, but under these conditions, suffering mental stupidity from the discouragement, he is unable to do anything beyond the first step. This student then waits until the instructor can help with the second step and so on. Sometimes this condition prevails with the strongest of minds, especially with girls. We have had experience with bright students who could master text-book lessons in the finest kind of way but who went at laboratory work with a discouraged mind, not being able to accomplish a thing even with a greater amount of help from the instructor, until that student was given a companion. We have had a few students in our experience to grow despondent, cry and give up before speaking of their troubles because they could not summon courage enough to tackle an exercise alone. We have never had that happen in a case in which two students were placed to work together. In many cases the apparatus to be worked with is complicated and requires more time of one student, in setting up and adjusting of parts, than is required in the performance of the experiment after the apparatus is arranged. It is inconvenient and expensive to furnish each student with all of the necessary apparatus with which to perform all of the experiment required, therefore much of the apparatus must be obtained from a general stock room. So a great deal of time must be wasted in making trips to and from the stock supply. The ideal way, of course, would be for the student to get all of the apparatus in one trip and return all in one trip. But we have observed that in the majority of cases two or three trips have to be made before all apparatus can be put into form. The same might be said as to weighing and measuring materials. Two people can get this sort of preliminary work done in one half the time required for one to do it. Heating water, generating gas, washing and placing away apparatus is another sort of work which can be done in less time if two students are working at it. Oftentimes wasteful mistakes are made by individuals or groups. If two people are working together, one is caught by the other in the mistake and the error is corrected before it is too late. We have more often seen the entire train of apparatus taken down and set up again by the individual student than by the pair of students working together. Time is saved also by students checking on each other as materials are placed together for reactions. In passing written tests on laboratory work those who have worked alone emphasize the mechanical part of the work more than they do the chemical. This is a habit that beginners in laboratory work are inclined to practice too much under best of circumstances, and if we wish to train against it we must make the conditions such that the chemical fact is the fact that is uppermost in the mind of the student as the work proceeds. For example, if the student is left alone to carry out. the process of preparing water by reducing copper oxide with hydrogen, the tedious and difficult work of setting up the apparatus will have made such a deep impression on his mind that he will have lost track of the chemistry of the process, and when he is called upon to tell about the preparation of water by a gravimetic method he will begin and proceed as follows: "Place mossy zinc in a flask fitted with a delivery tube and a dropping funnel, fill the dripping funnel with hydrochloric acid, attach the delivery tube to a combustion tubecontaining copper oxide, arrange at the opposite end of the combustion tube some "w" tubes containing calcium chloride. Heat the combustion tube with a Bunsen gas burner as you drop the hydrochloric on the zinc. The weight of the tubes before and after the process represents the water formed.” Then if any question were raised about the description, the student would claim he deserved full credit for knowing the process because he did as he was told. If the time of arranging the stopper delivery tube and funnel in the flask could be reduced to a minimum and more discussion about the preparations of zinc and hydrochloric to generate the hydrogen and less time and trouble in arranging the combustion tube and more for discussing the copper oxide heating to aid in the reduction of it with the hydrogen, then less time to the adjustment of the potash tubes and more for the discussion of the absorption of the water, the student might get the chemistry better. When two work together this necessarily reduces the time for the mechanical part. If reasons for arranging the apparatus thus and so present themselves and that part of the work proceeds, two people co-operating will of necessity discuss the problems and more quickly arrive at the correct conclusion. Then if the heating process, in an experiment like this, or the boiling or any such process in any experiments proceeds, two people can utilize the time to just as good advantage as if one at one experiment and another at another experiment could utilize the same amount of time. It is really better for both students to have the same spare time on the same experiment than for two students to have some spare time on different experiments, or better yet, than if their spare time comes at different times on different experiments, for they cannot be prevented from taking each others' time discussing, asking each other questions and distracting each other. In considering students' dispositions, we seemed to see advantages for certain students working alone. In the setting up of apparatus this type of student would take more pleasure in doing the work alone than in having help, and to hear him express it he would rather do it in his way than to watch the awkward student fumble with the materials and if he has done the same identical work before and does not need the drill, he takes all the more pleasure in doing it himself, and all the more displeasure in watching a partner do his part. He is like the executive who would rather do the work than to try to get the other fellow to do it. In other words, he has not the elements of an executive. He may make a good technical worker, and the best thing for him is to have him work alone. This type of student also likes to do his own thinking and, |