| (NB This unit is written from an unashamedly constructivist viewpoint. You may of course wish to emphasise, to those with whom you discuss the nature of science, particular flavours of constructivism, to be critical of the framework used here or provide alternative or additional perspectives – but as tutors, or students, we must own our own ‘story of science’.)
Children do not come to science as 'blank slates to be written on'. They have ideas about why things happen. These naïve ideas are likely to differ from the accepted scientific view, and may remain uninfluenced, if our teaching ignores them. This
Ideas and Evidence unit explores the way science teachers can help children
construct an understanding of their environment that accords with current scientific ideas. This is achieved through the construction of new scientific ideas or theories.
Although these scientific ideas are products of our imagination (or at least the imagination of scientists who thought them up), they do have to stand up to rigorous testing and critical evaluation from those who use the ideas in their own work, often in other fields of study, be they scientists, technologists, teachers or students (other scientists may have different ideas too). The
Investigative Skills unit examines the experimental and investigative side to science, and covers, amongst other things, the idea of making fair tests.
The Science Enhancement Programme (SEP) has developed some important and very useful materials to help teachers develop their approaches to teaching this section of the science curriculum, and this unit makes full reference to this material.
2.1 Personal elicitation
Trainees, like pupils in school, need to be challenged with questions that elicit their personal ideas about the nature of science so any misconceptions can be addressed. The questions that follow are based on areas that have confused children and students alike. Further details can be found in the PowerPoint presentation, download
2.1a Look at the ‘notes’ section for information on how to use the presentation.
These four questions can be posed to students to begin the process of understanding the Ideas and Evidence strand of the National Curriculum, and more generally to understand how science works. Discussion of these two questions follows in section
2.2 Guesswork and Checkwork.
1) Which model of science do you agree with and why?
| Science as Objective |
Science as Human endeavour to understand and control the physical world |
| Capable of yielding ultimate truths |
Producing knowledge which is tentative, always subject to challenge by further evidence |
| Proving things |
Creating new, testable, ideas |
| Having a defined and unique subject matter |
Building upon, but not accepting uncritically, previous knowledge and understanding |
| Having unique methods |
A social enterprise whose conclusions are often subject to social acceptability |
| The same for everyone |
Constructed in the minds of individuals but developed in a social context via language and critical debate. |
| Being value free |
Constrained by values |
2) If you wrap a block of ice cream up in a blanket, will it melt faster, slower or at the same rate as the unwrapped one left in the same room at room temperature?
3) What is the function of the wax in a candle?
4) Get pupils in your class to “Draw a scientist”
 |
Download
2.1a 'Ideas and Evidence' contains some suggested workshop activities for trainee teachers to undertake following their first experience in school to consolidate their understanding of the Ideas and Evidence strand. |
(Presentation of the initial elicitation questions and introduction to the topic.)
2.2 Guesswork and Checkwork
Karl Popper (1959) and later philosophers realised that
Science progresses by people having ideas (Popper’s Conjectures,
Medawar’s (1969) guesswork), which then have to be
tested against ‘reality’ (Popper’s Refutations
and Medawar’s checkwork). This is reflected in the
right hand column in the table in question 1 above. [NB
Conjectures/guesses are not unconstrained - they are ‘educated’
guesses based on previous experience (or trusted information
sources). One problem is that when we have a reasonable
theory that seems to explain something, we no longer
tend to ask questions or consider it worthwhile to do
experiments. Perhaps teachers should more often encourage
students to ask questions and test their answers? This
should avoid the unkind - although too often true -
caricature of school science as ‘telling children the
answers to lots of questions that the children have never
even thought of’!]
In the ice-cream question (q.2) above, many children (and
adults) may have an idea that blankets are intrinsically
warm, so the ice-cream will melt faster if wrapped in a
blanket. This is the conjecture or guess. It
is an idea or theory which we then have to test against ‘reality’.
When the experiment is performed many are surprised that the
wrapped ice-cream stays frozen longer then the unwrapped
one. This result means that they have to re-visit their
theory about blankets being warm. Perhaps they will recall
that beds are not warm until a living person enters them. A
new idea would be that the blanket is a barrier to the flow
of thermal energy, so the heat generated by the body remains
in the bed. It is not the blankets that are warm, but they
are acting as a barrier. Thus in the case of the ice-cream,
the heat from the room gets to the unwrapped one quicker
than the one wrapped in a blanket.
This view of how science works has an exact parallel to constructivist
ideas about teaching. Children make imaginative guesses
to explain phenomena around them, and fair testing
allows them to make consistent and valid tests to check
if their ideas can be believed in. Scientific ideas
have changed over the centuries, and are still changing
today. What we tell children is our ‘best guess’, and we
need to give them a flavour of both the creative guesswork
and the rigorous checkwork that is at the heart of
our scientific understanding. This unit has a focus on the ideas
(guesswork), and the linked unit, Investigative Skills,
deals with the testing (checkwork) of ideas.
See P1.6
History and philosophy of science and science education
in the Professional Issues section of sci-tutors for more on
this, and, for children’s ideas, see Professional
Issues/Teaching/Misconceptions.
The problem in school is how to put over this picture of
how science works, for, although science teaching in the UK
is dominated by practical work, time restraints mean that
many of the activities pupils do are tightly structured,
rather like following a recipe. Chapter 1 in Teaching
Secondary Science (Ross et al. 2004) has a section
describing eight activities involving the process of rusting
(pages 7-10). They are designed to help secondary trainees
focus on the role played by practical work in science
lessons, and they are asked to decide, for each activity:
- Which of these are best in helping pupils to understand
what happens during rusting? (pupils may, for example,
think the iron ‘rots’ like wood - an idea we need to
challenge.)
- Which give a good picture of the process of
being scientific? (guesswork followed by checkwork).
- Which are unhelpful in both respects? (Perhaps because
they are too complex, or are recipes that pupils can
follow without thinking)
2.3 Steps in forming an explanation and developing a scientific concept
Pupils find problems with elicitation question No 3
(Para. 2.1) - What is the function of the wax of a candle?
The more wax there is the longer the candle lasts. Wax drips
down the side. It seems that the wax is retarding the flame
- slowing the burning of the wick. A Y6 child said 'the wax
is fireproof' See PowerPoint
download in children's ideas unit
How can we, as teachers, challenge this view, and show
that burning is a constructive process where it is the wax
which burns, joining with the air producing oxides? How can
we persuade children that the wax is the fuel?
The act of challenging pupils’ naïve ideas and
comparing them with those accepted by the scientific
community not only helps children understand the nature of
our world, but also helps them appreciate the way in which
scientific progress is made.
2.4 Images of a scientist (question 4)
Somehow we need to convince our student teachers and they
need to convince their pupils, that we are all scientists.
The way we all learn about our environment is by guesswork
followed by checkwork. Maybe not formally, nor rigorously,
which is where the science teacher has a part to play. See
slides 17-20 of download 2.1a Pupils' images of the scientist may be very narrow and stereotypical.
Download 2.4 is taken from the BEd Secondary course at the University of Lancaster and gets students to examine the way ideas about forces developed over historical time and can be applied to everyday activities and may help to broaden their view of science and scientists.
3.1 The Science Enhancement
Programme (SEP)
The work done by the Science Enhancement Programme for
Key Stage 3 has implications for teaching about the nature
of science at all ages.
Teaching about Ideas and Evidence in Science at Key Stage 3
A project funded by Key Stage 3 National Strategy and
Science Enhancement Programme
The material is available on CD-ROM and includes examples
of classroom activities with notes for teachers and pupil
materials.
The materials have been collated by a team of science
educators working in five Universities involved in initial
teacher education.
Martin Braund - University of York
Sibel Erduran - formerly King’s College London, University
of London
Shirley Simon - Institute of Education, University of London
Keith Taber - University of Cambridge
Rob Tweats - Keele University
You need to visit the web pages and link to the whole
project, but here is one quotation to whet the appetite:
At present, many pupils are learning science as
isolated fragments of knowledge, and this does not allow
them to appreciate how ideas come about, or how they may
not always apply, or why they may not always lead to
precise predictions. Pupils often see theories as facts,
which have been proven, because science is often presented
that way. If pupils could spend more time seeing how ideas
develop, and how they change, they would better appreciate
the nature of scientific knowledge, and the great cultural
achievements of science.
3.2 First -hand evidence and the role of language in developing ideas
Children are more likely to make links between their
existing naïve ideas and scientific ideas if teachers
present ideas which are related to the children's
experiences. So, to establish such links we need to
encourage children to relate everything to their own
experiences and to put forward their existing explanations.
They are then allowed to test predictions against their
existing and against the new (teacher presented) ideas. See
paragraph 2.2 above for an example of this approach.
Investigations in science are the tool for rearranging
their existing explanations into more generally accepted
world views. When children are working in groups their ideas
can be brought out into the open and verbalised - this
verbal exploration allows their thinking to be tested.
Talking is essential to learning, and exploratory talk
is needed for children to be 'in charge' of their
learning. No college student will write an assignment
straight into 'best', no politician will write their speech
directly as the final version. This web-page was not written
once and never amended. We all need to draft our ideas first
- and the first draft is best done verbally. In school this
will allow children to make sense of things - only then
might it be sensible for them to try to make a written
record.
We need, too, to be careful in our judgement of
children’s ideas. Their use of a word does not indicate
that they have a grasp of its public or scientific meaning.
They may have the right concept but using the wrong word.
For example, if a child says, 'A ton of feathers is lighter
than a ton of lead', the statement is true if by 'lighter'
the child means less dense, but false if they mean the
reading on a weighing scales.
Several examples are needed to illustrate an idea because
the existence of different meanings only comes to light when
a range of situations are explored. For example, see how the
meaning of the word animal changes with context:
No animals allowed in this shop.
We, like other mammals, feed our young on milk, and mammals are animals.
The implication is that a wide range of experiences is
necessary to challenge children's ideas.
Ideas change as children become older (in the reception
class humans are definitely not animals, by Y6
they are beginning to be so but by Y11 at the age of 16 humans
are certainly classed as animals).
What can teachers do?
1) Accept that children's ideas can influence
teaching.
2) Be aware of children's ideas on a topic.
3) Provide first hand experiences before discussing ideas.
4) Encourage children to express ideas and appreciate
other views verbally.
5) Value new ideas by using them to solve problems and
make sense of experiences.
6) Realise that communication is important.
Research into children's ideas has mainly concentrated on
the conceptual side of the National Curriculum. An excellent
account of children's views about the nature of science and
how science happens is in Driver et al (1996). Research
suggests that children see no point in scientists doing
experiments if they already suspect what might happen. Most
children have a 'eureka' view of science. A scientist does
an experiment, not knowing what might happen and suddenly
out plops a discovery at the end.
Driver suggests that it is not until pupils sit their
GCSE that they truly begin to see the purpose of experiments
as testing ideas - that scientists do know what they
think (and hope!) will happen, because they are testing an
idea that they are trying to believe in. This is why medical
trials are done 'double blind', ie half a population of
people in a trial are given a 'placebo' with no drug in it,
and neither the patient nor the doctors know who is taking
the real drug. So if the effect is purely psychological, all
the patients get better. If the doctors are allowed to know
who has been given the drug, they may 'see' an improvement
in the treated patients that is not really there.
When scientists do observational experiments on complex
systems that they cannot manipulate (e.g. the behaviour of
animals in the wild), complex statistical methods are
required to determine if a particular observation could have
happened by chance or whether it might be 'real'.
To begin with pupils need experiences. Much of the
science we present to pupils in school, especially in the
early years, provides them with new experiences, or examples
of phenomena that they will find hard to distinguish in
their real world (e.g. magnetism, electricity, growth of
plants). It is only when they are aware of the phenomenon
that can we begin to get them to think about ideas and
explanations, causes and relationships.
The right hand column in the elicitation question no 1 in
paragraph 1 above gives a provisional, negotiated view of
scientific ideas - a view that scientific ideas develop and
change, not only in the scientific community as a whole but
in children as they experience more of the world.
At KS3 and 4 we need to help pupils assume the role of
being a scientist within the constraints of the school
laboratory. This process involves thinking and is not just
practical. Pupils need to predict what will happen and only
then test their ideas and expectations. A successful
investigation needs purpose - something that the pupil can
relate to and have empathy with. Investigations need to be
seen as a part of the activity of the wider scientific
community, not a way of getting marks at GCSE, however
important that also has to be. The new orders for GCSE will
help to bring back this sense of purpose into
investigations. http://www.qca.org.uk/10963.html
- NCC (1993) Teaching Science at Key Stages 1 and 2 York:
National Curriculum Council
- CCW (1992) Science - Starting with Children's Ideas
Cardiff: Curriculum Council for Wales
- Driver et al (1996) Young People's Images of
Science Buckingham: Open University Press
- Osborne, J., Erduran, S. and Simon, S (2006) Ideas,
evidence and argument in science education. Education
in Science pages14-15 Number 216 February 2006
- Ross K (1998) Brenda Grapples with the Properties
of a Mern in Littledyke M & Huxford L (eds) Teaching
the Primary Curriculum for Constructive Learning London:
David Fulton
- Ross, K.A., Lakin L. and Callaghan P. (2004) Teaching
Secondary Science - constructing meaning and developing
understanding. Second Edition. London: David Fulton.
- Ross, K.A., Lakin, L and Burch, G (2005) Science
Issues and the National Curriculum CD-rom.
Cheltenham: University of Gloucestershire
- Sutton, C. (1992) Words, Science and Learning,
Buckingham: Open University Press.
- Teaching about Ideas and Evidence in Science at Key Stage 3
A project funded by Key Stage 3 National Strategy and
Science Enhancement Programme
Other References
All the websites were accessed on 8 March 2006
Downloads in this Unit:
Section Developed by:
Keith Ross, University of Gloucestershire with
support from Alan Goodwin and Aftab Gujral
March 2006
|
|
