Open Learning
After completing a few experiments, we felt
that it was important that students heard from
teachers who had experience of teaching using
inquiry-based methods. One morning the students
visited a local school to talk to a teacher who
specialized in open teaching techniques as proposed
by the German science education specialist Martin
Wagenschein ( 1968 ). The students heard about the
teacher’s experiences and ideas, and were shown how
one simple lesson could be transformed to make it
more open-ended by letting schoolchildren make the choices and decisions in the classroom instead of
the teacher. The teacher emphasized the importance
of getting schoolchildren to be active and involved
during lessons, and the importance of teacher
questioning in promoting schoolchildren to think for
them self.
How does a candle burn?
One good example of open teaching is the
study of how candles burn (Theophel, 1995). To start
this practical activity students were given the
question ‘How does a candle work? Students were
given candles, asked to light them, and then asked to
observe and draw a candle flame. A class discussion
followed where students described a candle flame.
During the discussion the tutor gave the class no
direction or information, but used questioning to
make students observe the candles more closely and
to describe what they saw. Can you see anything
else? What about the wick? What about the wax?
Although students started out with rather simple
descriptions, by this questioning a more detailed
description began to be drawn out.
One student observation was ‘as the candle
burns it gets shorter.’ This prompted the question and
problem ‘Where does the wax go to?’ from the tutor.
The students were unable to answer this definitively.
The tutor suggested some experiments. First the
students were instructed to blow their candles out,
‘What did you see?’ There were sometimes plumes
of white smoke, and the students concluded this was
wax steam leaving the candle, and that this was what
burnt in the candle flame.
Next the tutor suggested that students, with
the use of tongs, place a slide over the flame.
Students observed that black soot collected on the
slides in large patches. The tutor then prompted
students to place a slide actually into the center of the
flame. Soot collected in a ring shape, with the center
of the ring which had been held in the middle of the
flame being clear of soot. The students thus
concluded that smoke is only produced at the outside
of the flame, and not in the middle. One student
thought this was because the center of the flame was
the hottest and that the soot was simply burnt away
without collecting on the slide.
The tutor suggested an experiment using
wooden splints, by placing a splint for only a split
second in the flame you can see where the wood
begins to burn and is hottest. This took some practice,
but the students began to see that the wood that was
in the outer parts of the flame burned, while that
which had been in the center was not burnt; therefore
the center of the flame is cooler than the outer part.
The tutor then explained that in a candle flame the
outside burns hotter because there is more oxygen
available to the flame; in the center of the flame there
is not as much oxygen and it does not burn as well.
The aim of the practical was to show
students that often things that seem simple can be
quite complex, and that a good teacher instead of
telling students the answer, prompts students with
good questions to see, observe, and think of the
answers for themselves.