3 The determination that the expected either does or does not happen,
with examination of reasons and elimination of disturbing causes in the
latter case.
4. The accepting as true of the classification and explanation already
given. Theories, explanations, and laws are thus accepted every day by
minds which could never have originated either them or the experiments
from which they were derived.
The method of original investigation, strictly considered, presents
many difficulties. A long course of preliminary training--a thorough
knowledge of what has been done in a given field already--a quick
imagination--a genius for devising forms of apparatus which will enable
him to work well under particular conditions in the most simple and
effective way--the faculty of suspending judgment, and of seeing
what happens, all that happens, and just how it
happens--patience--caution--courage--quick judgment when a completed
experiment presses for an explanation--these are some of the
characteristics which must belong to the original worker.
Were we all capable of doing such work there would be these advantages,
among others, of studying for ourselves:
1. What we find out for ourselves we remember longer and recall more
readily than what we acquire in any other way. This advantage holds true
whether the facts learned are entirely new or only new to us. Almost
every man whose life has been spent in study has a store of facts which
he discovered, and on which he built hopes of future greatness until
he found out later that they were old to the knowledge of the world he
lived in. And these things are among those which will remain longest in
his memory.
2. Associated facts would be learned in studying in this way which would
remain unknown otherwise.
But all the advantages would be associated with disadvantages too. Long
periods of time would have to be given for comparatively small results.
The history of science is full of instances in which years were spent in
the elaboration of some law, or principle, or theory which the school
boy of to-day learns in an hour and recites in a breath. Why does water
rise in a pump? Do all bodies, large and small, fall equally fast? The
principles which answer and explain such questions can be made so clear
and evident to the mind of a pupil that he would almost fancy they must
have been known from the first instead of having waited for the hard,
earnest labor of intellectual giants. And science has gone on, and
for us and for our pupils would still go on, only as accompanied with
numerous mistakes and disappointments.
What method shall we adopt in the teaching of science? It must
differ according to the age and capacity of the pupils. An excellent
modification of the method of original investigation may be arranged as
follows:
The children are put in possession of all facts relating to conditions,
the teacher explaining them as much as may be necessary. The experiment
is performed, the pupils being required to observe exactly what takes
place, the experiments selected being of such a nature that any previous
judgment as to what ought to occur is as nearly impossible as may be. We
predict from knowledge, real or supposed, of facts which are associated
in our minds with any new subject under consideration. Children often
know in a general, vague, and indefinite way that which, for the sake of
a full and systematic knowledge, we may desire them to study. What
they know will unconsciously modify their expectations, and their
expectations in turn may modify their observations. We are apt to
believe that happens which we expect will happen. There ought to be no
difficulty, however, in finding simple and appropriate experiments with
which the child is entirely unacquainted, and in which anything beyond
the wildest guess work is, for him, impossible. The principal use which
can be made of this method is in the mere observation of what takes
place. Nothing which the child notices correctly need be rejected,
no matter how far removed from the chief event on the object of the
experiment. Care that the pupil shall see all, and separate the
essential from the accidental, is all that is necessary.
But the original investigator assigns reasons, and with care the
children may be allowed to attempt that. This, however, should not be
carried far; incorrect explanations should be criticised; and the class
should at length be given all the elements of the correct explanation
which they have not determined for themselves. Later, pupils should be
encouraged to name related phenomena, to mention things which they
have seen happen which are due to associated causes, and to suggest
variations for the experiment and tests for its explanation. Good
results may be made to follow this kind of work even with very young
pupils. A child grows in mental strength by using the powers he has, and
mistakes seen to be such are not only steps toward a correct view of the
subject under consideration, but are steps toward that habit of mind
which spontaneously presents correct views at once in study which comes
later in life.
Another method is this: The pupil may know what is expected to happen,
as well as the conditions given, and held responsible for an observation
of what does happen and a comparison of what he really observes with
what he expects to observe. Explanations are usually given a class,
often in books with which they are furnished, instead of being drawn
from them, in whole or in part, by questioning, when physical science is
studied in this way. Indeed, this method is a necessity when text books
are used, unless experiments from some outside source are introduced.
Who shall perform the experiments? With young pupils everywhere, and
in most of our common, and even in many of our graded schools, the
experiments must be performed by the teacher. With young pupils the time
is too limited, and the responsibility and necessary care too great to
permit of any other plan being practical. In many of our schools the
small supply of apparatus renders this necessary even with larger
pupils. Added to the reasons already given is the important one that in
no other way--by no other plan--can the teacher be as readily sure that
his pupils observe and reason fully for themselves. In this normal
school a course in physics, in which the experiments are all performed
in the class room by the teacher, is followed by a course in chemistry,
in which the members of the class perform the experiments for themselves
in the laboratory. And, notwithstanding the age, maturity, and previous
observation of the pupils, a great deal must be done both in the
laboratory and in the recitation room to be sure that all that happens
is seen--that the purpose is clearly held in the mind--that the reason
is fully understood.
With older pupils and greater facilities, however, the experiments
should be performed by the pupils themselves. Constant watchfulness is
necessary, it is true, to insure to the pupil the full educational
value of the experiment. With this watchfulness it can be done, and the
advantages are numerous. Among them are: