Dear JA --
I think it’s useful to think in terms of different
kinds of investigations. The dictionary definition of ‘investigate’
is to ‘observe, study or closely examine’. All the practical work involving
first hand study of materials would therefore be called investigation
(or inquiry, since this is defined in terms of investigation).
There are different kinds of investigation, however,
which emphasize different process skills and are appropriate for investigating
different kinds of questions. The main types are:
- information-seeking -- investigations carried
out to see what happens, either as a natural process unfolds or when
some action is taken, e.g., seeing eggs hatch, raising butterflies
or silk worms, observing the expansion of water on freezing, seeing
what things dissolve in water. They emphasise observation and communication
skills. They are relevant at all stages but particularly for younger
children.
- comparing or fair testing -- investigation
that often begin from a ‘which is best?’ question. Which detergent
washes the clothes best? Which fertilizer is best for the plants?
Which paper towel is best for mopping up water? The first step in
these investigations is to turn the question into an investigable
one by specifying the meaning of ‘best’ in a way that identifies the
basis of comparison. So ‘which type of sugar dissolves best?’ has
to be turned into, for example, ‘which type of sugar dissolves most
quickly?’ These are popular and useful investigations since they involve
children in identifying and controlling variables (amount of sugar,
amount of water, temperature of water, presence or absence of stirring,
etc). They also have the appeal of yielding information about real
things from the actions carried out by the children. However it’s
necessary to avoid a routine or formulaic approach, when the value
for thinking becomes diminished.
- pattern-finding -- investigations that
apply where there is a relationship to be found between variables,
e.g., the note produced by blowing across the top of a bottle with
different amounts of water in it; the direction of a shadow cast by
the sun and the time of day; the number of turns given to a wind-up
toy and how far it will go. These investigations involve the same
skills as ‘comparing’ investigations since the effect of changes in
one variable have to be tested fairly, with other variables or conditions
kept the same, but there is the added emphasis on interpreting data.
- hypothesis-generating -- investigations
which seek explanations to things such as: the appearance of dew on
grass overnight; the misting of windows in certain conditions; the
echo of foot-steps in some places; the behaviour of a ‘Cartesian diver’.
The explanations are often in terms of the conditions or events that
are associated with these observations rather than general scientific
principles. The investigations begin with open-ended exploration of
the phenomenon leading to the generation of a range of possible explanations.
These can be checked against the evidence so far available by using
the hypotheses to make predictions.
- how-to-do-it investigations -- investigations
where the end product may be an artefact or a construction that meets
particular requirements – a model bridge that will support a certain
load, for example.
As you can see, each has a particular emphasis and
relevance to certain types of problem or question. In each case it’s
important to enable children to plan the investigation and not to by-pass
this by giving them instructions to follow. They will only use and develop
the skills by doing the thinking for themselves. There must, therefore,
be opportunities for children to start from a question and work out
how to answer it, or to make a prediction and to think out and carry
out their own procedures for testing it. Motivation to answer a question
arises from 'ownership of it, so students must be involved in raising
questions for themselves.
To take these steps by themselves is asking a great
deal of young children and of older ones unused to devising investigations
and they will need help which subsequently can gradually be withdrawn.
Young children's experience should include simple problems such that
they can easily respond to 'how will you do this?' For example, 'how
can you find out if the light from the torch will shine through this
fabric, this piece of plastic, this jar of water, this coat sleeve?'
Often young children will respond by showing rather than describing
what to do.
With greater experience and ability to 'think through
actions' before doing them they can be encouraged to think ahead more
and more, which is one of the values of children devising their own
investigations. Involving children in this is part of setting an expectation
that they will think through what they are going to do as far as possible.
For older children, help in devising and planning
can begin, paradoxically, from reviewing an investigation which has
been completed (whether or not the children planned it themselves),
helping them to go through what was done and identifying the structure
of the activity through questions such as
- what were they trying to find out?
- what things did they compare ( identifying the
independent variable)?
- how did they make sure that it was fair ( identifying
the variables which should be kept the same)?
- how did they find the result (identifying the
dependent variable).
- how did they use the result to answer the initial question?
When devising a new investigation the lessons learned
from reviewing a previous one can be recalled, where perhaps variables
were not controlled or initial observations taken when they should have
been.
The teacher's role in this development can be summarised
as:
- refraining from giving instructions which prevent
children thinking for themselves
- providing time and a structure for planning
- expecting children to think through what they
do even it they do not write formal plans on paper for every investigation
- reviewing plans in the light of what was done.
Thanks for your questions.
Wynne