Teaching and Popularizing Science

Competence, involvement and enthusiasm of the lecturer are usually
highlighted as the principal components of success in science and
mathematics teaching. While these are important, the capacity of the
students to absorb the message is often neglected -- their minds are
considered mere empty receptacles ready to be filled with information
that
emanates from the learned person on the rostrum. Such an approach
overlooks the basic findings of cognitive science. Since the late 1950s
it
has suggested new, appropriate methods of information and knowledge
transfer which recognize the mental state of the learner.


[5~I have a cartoon that shows the skull of a student wide open with an
instructor pouring in something (information?) from a jug! But a
learner's
mind isn't an empty container waiting to be filled. She comes to the
class
or a popular lecture with a history of ideas and a model of the world in
her
mind. But her intuition and "gut-feelings", while valuable in making
sense
of everyday phenomena, often lead to serious misconceptions. When her
"naive" theories are fixed in the mind they become hurdles to a rational
understanding of old and new phenomena. Even the great and famous are
susceptible to this.


Aristotle believed that men had more teeth than did women. His
stallions
had more teeth than the mares, so he deduced that human males had more
teeth than women. That for a man who married twice! This misconception
isn't anywhere as serious the one that held back the development of
mechanics and hence the sciences for centuries. Aristotle believed that
heavier objects accelerated faster than lighter ones, and that a body
travelling at a higher velocity than another was experiencing a larger
force.
While these ideas still seems intuitively correct, they are most
definitely
wrong, but it took 1500 years and the appearance of Galileo to prove
this.


Ask a person on the street or a young student about the forces acting on
a cricket ball in flight. It is likely that some will be able to
identify the
gravitational force, and the drag due to air friction on the ball. But
several
will introduce a force in the direction of motion which they will assign
a
high value if the ball is headed out of the ground, and a lower value if
it
were to land in the hands of a mid-field player. The average punter's
intuition, like Aristotle's, can be wrong.


Learners use naive theories to explain their experiences long before
getting
science lessons. These theories are used to understand and explain new
ideas and problems -- ones that differ significantly from those tackled
in
class or seen in textbooks. For instance, they attach naive meanings to
technical terms such as acceleration, and they may retain this
throughout
their lives.


Science is sometimes taken to be a mere quantitative gymnastics.
Successful numerical problem-solving, though, requires substantial
amount
of qualitative reasoning. Expert problem solvers first try to
understand the
problem by constructing alternative representations and links between
the
relevant parameters. After the situation is understood qualitatively do
they
start working on its quantitative aspects.


Understanding the role central roles of both naive theories and
qualitative
analysis points to a new mode of teaching. Here we will only elaborate
some of the fundamental points on which there is agreement among
cognitive scientists, and teachers who practice them.


First, learners fits new phenomena or new information into an existing
framework which they have gained or constructed through past experience
and formal learning. Naive theories always get constructed as part of
this process. Often scientific theories taught in schools cannot
compete
as reference points for new learning because they are presented quickly
and abstractly and so remain unorganized and unconnected with past
experience.


A teacher with a large class may seem faced with a hopeless task of
first
unearthing the naive theories of each student and countering them. This
is
not the case, however, since students have similar misconceptions, and
it
is these that the teacher needs to concentrate on. The teacher gains
knowledge of these naive theories by close interaction with students and
by knowing the literature on the common misconceptions.


Merely stating in class that the Aristotelian theory of force is
incorrect
fails to be recorded. Nor will stating Newton's second law help make
the
truth register deeply. Naive ideas are deep-rooted and need to be
weeded
out forcefully. The teacher will need to provide some striking physical
and theoretical demonstration of the falsehood of Aristotle's idea. Or
she should suggest an experiment that students can do by themselves --
one
with sufficiently surprising results which can destroy misconceptions.
A
bulb should light up in the students mind! If scientific theories and
rational explanations become available to children from an early age,
naive theories do not invade their minds.


Second, to understand something is to know relationships. Experts store
knowledge in clusters that they use to interpret familiar situations and
to reason about new ones -- one would like students to emulate this.
Bits
of information isolated from these structures are forgotten or become
inaccessible to memory.


This suggests that teachers should help the students acquire the skills
to
create, manipulate and build cross-linkages between their knowledge
clusters. In addition, in-depth qualitative reasoning needs to be
taught.
Tests of these ideas in class-rooms have shown that students trained in
this
mode are superior performers than others.


The new ideas have relevance to all kinds of teaching and learning --
not
just mathematics and science. They also have implications for science
popularizers whose mere statements of fact or rational explanations of
phenomenon fail to register with the audiences. Striking demonstrations
that destroy deeply entrenched ideas are essential -- it is through them
that minds open and newer pathways of understanding develop. These are
the challenges that educators face in Pakistan.




This article on was published in The News, a national daily, on Oct 7, 1997. It formed the basis of a talk Mr. Daudpota delivered at a conference on Science Popularization in Islamabad.