Missionary Field Notes
Clifford Swartz
Your call has come. Perhaps you have a child in the class. Perhaps
your college is forming an alliance with the local schools. Perhaps
your company is making a goodwill gesture to the community. For some
such reason, you have been invited to speak about physics to students
in high school or elementary school. Now what?
You'd better make sure of what the school expects, and see if there's
an overlap with what you expect. It may be that you've been invited
to fill the opening in the assembly schedule because the village magician
had to cancel. Can you bring your bed of nails? Are you being invited
for show-and-tell, or to describe your specialty which is outside the
standard curriculum, or to be a substitute teacher on some standard
topic?
There's some justification for a little razzle-dazzle show-and-tell.
The only scientist I ever met before college produced dry ice in my
glove by flooding it with CO2 gas. I thought that was pretty neat,
although I was only eight years old and didn't understand the science
involved. I doubt that it had anything to do with my future interest
in physics. Still, a lot of our colleagues take science shows on the
road and apparently spark great interest in their school audiences.
Unless the scientist dresses up like Dr. Wizard, the kids can find
out that not all scientists are mad and can get a sense of the excitement
and fun of science.
Even when entertainment is the chief ingredient of the visit, the
students should be brought into the act. They can be the foils. The
long- haired girl (or boy) can hold onto the Van de Graaff; the tallest
student can drop two objects at the same time; the strongest student
can try to pull apart the Magdeburg hemispheres. No matter what the
purpose for your visit, don't lecture non-stop. The younger the audience,
the shorter their attention span. On the other hand, don't require
continual student activity. Get them out of their seats, and then get
them back for awhile.
A lot of physics demonstrations are portable, safe, and entertaining.
Before settling on just entertainment, however, consider the point
of your visit. What does the teacher expect to happen, and what do
you expect to accomplish? Never mind what the students expect. Students
do not think of school activities as being any of their business.
A safe rule for any one teaching session, whether for young or old,
is that only one idea can be explored. You must leave time at the beginning
to describe that idea explicitly, then demonstrate the idea, and then
leave time at the end to tell the audience what you have demonstrated.
If the main idea is to show students that physics can be fun, then
plan your activities so that both you and they have fun. However, you
are in a school during school time and there should be more substantial
results than just fun and games during one hour. Is your point that
professional physicists are human and have fun? That might be a valuable
moral, but not many of these students will be professional physicists,
no matter how much fun you have had. Is your point that the students
will have fun studying more science--perhaps enrolling in physics?
Better talk this over with the science teachers. Their courses may
be no fun at all. If your visit is intended to be a recruiting drive,
you should be very familiar with what you are selling, and then make
the pitch explicitly.
Perhaps your visit is intended to supplement the regular syllabus
because your specialty is related to the topic the students have been
studying. Now lots of prior consultation is called for. The teacher
should tell you in detail what the class has been doing. Read their
textbook on the subject. You will want to use symbols familiar to them,
and take only small steps beyond what they have already learned. Find
out in advance if the teacher or book have been dogmatic about explanations
with which you may not agree, and where you must use some diplomacy.
(Another way to view this is ...).
If you really intend that your visit should be for teaching, then
the elements of teaching must be in place. The students must prepare,
they must interact, they must study, they must demonstrate that they
have learned. In the early days of Brookhaven Laboratory, one of the
local schools exploited the fact that many parents worked at the Lab.
About half of the fifth and sixth grade science classes consisted of
week-long projects involving a lab visit. First, a father-or-mother-scientist
would visit the class after prior discussion with the teacher. There
would be a combination of show-and-tell and student activity, leading
to a question or problem for the students to read about and talk about.
Then there was a visit to a particular activity at the Lab (not a general
sight-seeing expedition!). The problem was further demonstrated or
explored, now with real world equipment. For the next few days after
the visit the class discussed what they had seen, made models, wrote
reports, and usually had a test. This many-faceted activity took more
effort on the part of everyone, but we thought that the students learned
more. They certainly worked harder. They also had more fun.
There's another stricture about missionary effort. You not only have
to know your gospel; you have to know the heathen. There is no need
for you to be familiar with the current and local fads of the students.
You are an outsider and they will not expect it. But you should be
aware of the more universal characteristics of children and their learning
possibilities. Consider how you would teach six-month children to walk.
You would not lecture, or demonstrate, or give multiple-choice exams.
Even beating the kids will do no good. The only thing to do is to let
them mull it over for six months and then they will walk. Even as there
are obvious developmental stages in physical abilities, so too are
there stages of concept development. The nature of these was explored
and described by Jean Piaget and they are known by his name, though
to a large extent they are part of the common wisdom of dealing with
children. A century and a half ago, Joseph Henry described the stages
and the implications for science instruction. For our purposes, the
most important stage involves the ability of students to use symbolic
reasoning, such as algebra. Our school culture assumes that students
develop this ability during early adolescence, but probably two-thirds
of a standard population cannot understand algebra by the time they
are eighteen. On the other hand, some of these may be very good at
hearing and producing complicat- ed music, or in artistic expression,
or in dealing with words. Nevertheless, for teaching our science lessons
we must be aware of these stages and the age groups with which we can
employ various logical methods. Most third graders cannot understand
analogies; most sixth graders have no sense of sizes (or historical
times) beyond their own tangible experiences; most ninth graders do
not understand functional dependence of one variable on another; most
twelfth graders cannot easily use power-of-ten notation. Of course,
I am not talking about your children or mine, all of whom are precocious.
So you have been elected? You are to be visiting scientist for an
hour. Find out what the teacher expects. Search your conscience and
decide what one thing you want to accomplish. Take the time to learn
about your audience. Get them out of their seats and let them measure
something. Tell them what one thing they have learned. Try to arrange
a follow-up, for you and for them. When you're all done, ask yourself:
did they learn anything? Did you learn anything? Did you and they have
fun? Be careful. Teaching can be addictive.
- Clifford Swartz is Professor of Physics at State University
of New York in Stony Brook, NY. He was awarded the Oersted Medal
in 1987, and he has served as editor of The Physics Teacher for
many years.
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