Teaching and learning about the nature of
science:
Implications for physics teaching
Dr. Jim Ryder
School of Education
University of Leeds, UK
j.ryder@education.leeds.ac.uk
Outline
1. What is the Nature of Science?
2. Why teaching/learning about the Nature of
Science?
3. Students’ ideas about the Nature of
Science/Physics
4. Implications for physics teaching
World
Science
The Nature
of Science
A way of examining
and talking about
the world
Examining and talking
about Science
(‘Knowledge about
Science’)
The Nature of Science
1.
2.
3.
4.
5.
6.
7.
What are the purposes of scientific
investigations?
How do scientists design investigations?
How do scientists assess the quality of data?
What is the nature of scientific explanations?
What are the limitations of science?
How does the scientific community work?
(Internal sociology of science)
How do scientists/science knowledge interact
with social issues? (External sociology of
science)
The scientific method?
•
•
•
•
•
•
•
Observe phenomena
Develop question
Create hypothesis
Design experiment
Conduct experiment
Analyse data
Draw conclusions
Based on:
Windschitl (2004) Folk theories of ‘inquiry’: How preservice teachers reproduce the discourse and
practices of an atheoretical scientific method. Journal of Research in Science Teaching, 41(5),
p.481-512.
The scientific method?
“There is no such thing as ‘the scientific method’. A
scientist uses a great variety of exploratory
strategems, and although a scientist has a certain
(…) way of doing about things that is more likely to
bring success than the gropings of an amateur –
he uses no procedure of discovery that can be
logically scripted.”
Medewar, P. (1984) The limits of science. Oxford University Press, p. 51.
Objective observations?
• Do we simply ‘observe’?
• We use theories/ideas to interpret what we see
Standing on a hilltop at dawn two people are
observing the eastern horizon.
One says: ‘the Sun is rising above the horizon and
travelling up into the sky.
The other person says: ‘the Earth is turning, allowing
us to see the Sun above the horizon’
Science Explanations
Science explanations are more than descriptions of
phenomena/observations/data
DESCRIPTION
SCIENCE EXPLANATION
The Sun rises in the East
The Sun is at the centre of our
Solar System. The Earth spins on
its axis once every 24 hours.
A steaming hot cup of tea cools
down
Evaporation produces cooling
because the most energetic
particles leave the liquid.
In a simple circuit the bulb will
light up when the switch is
closed.
When the switch is closed the
charges in the wire form an
electric current which transfers
energy from the battery to the
bulb.
Models of the atom
Characteristics of explanations in science
Generalisable
particle theory of matter explains cooling through
evaporation, solid-liquid-gas phase transitions,
minimum temperature, expansion/contraction
Simplifying
Assumptions
magnetic field lines in two dimensions; ignoring
friction in dynamics; assuming a spherical Earth
Predictive Power
Particle theory of matter and minimum
temperature; Bohr model of atom and chemical
valency
Abstract ideas
Electron orbits, electron clouds; Mendel’s theory
of inheritance and ‘genes’,
Use of analogies
Light moving as a ‘wave’ through the ‘aether’,
Maxwell’s vortices
Mechanism
particle theory of matter provides a mechanism for
expansion of solids on heating
The role of chance and status in the
development of physics knowledge - the
discovery of the electron spin
I think that you [Goudsmit] and Uhlenbeck have been very
lucky to get your spinning electron published and talked
about before Pauli heard of it. It appears that more than a
year ago Kronig believed in the spinning electron and
worked out something; the first person he showed it to was
Pauli. Pauli ridiculed the whole thing so much that the first
person became also the last and no one else heard
anything of it.
Letter by L.H. Thomas to Goudsmit, 25 March 1926
It is indeed very clever but of course has nothing to do
with reality.
Pauli.
Outline
1. What is the Nature of Science?
2. Why teaching/learning about the Nature of
Science?
3. Students’ ideas about the Nature of
Science/Physics
4. Implications for physics teaching
The aims of scientific literacy 1
‘… much of the scientific knowledge acquired at
school is forgotten by adulthood. Rather, what is
needed is a much better understanding of the
practices, processes and limits of scientific
knowledge. Developing such an understanding is
essential if individuals are to be able to make
personal decisions and to participate in the public
debate about the moral and ethical dilemmas
increasingly posed by scientific advances …’
The aims of scientific literacy 2
‘…what is important is not that citizens should be
able to remember and recall solely a large body of
scientific facts, but that they should understand
how science works and how it is based on the
analysis and interpretation of evidence. Crucially,
citizens should be able to use their understanding
of science, so that science can help rather than
scare them’.
Scientific literacy should not be taken to
mean the knowledge of a lot of science,
but rather the understanding of how
science really works.
Durant, j. (1994) What is scientific literacy?, European Review,
Scientific theories are guesses that haven’t been proved yet. After the
theory is proven it will become a law. Vol. 2, no. 1, 83-89.
Science and ‘real life’: Interactions with
mobile phone technology
• Science concepts: e.g. source-receiver model of
radiation, non/ionising radiation…
• Technology: use of network of base stations,
directivity of the beam…
• Nature of Science: the need for a large sample in
studies, difficulty of designing studies over a long
period of time outside of the laboratory.
Science and ‘real life’: Interactions with
mobile phone technology
The case of a parent who was convinced that moving
her child away from a school sited near to a mobile
phone mast was the cause of a dramatic improvement
in her child’s health:
‘she’s a different child now – it’s all the proof I need to
convince me there is a link between those wretched
masts and the health of children’
(Burgess, 2004, p. 1).
School Science
Science in a
Public Domain
Established knowledge
Contested knowledge
Hard facts
Complex, ‘real world’
contexts
Ready Made
Science (Latour)
Science in the
Making
Outline
1. What is the Nature of Science?
2. Why teaching/learning about the Nature of
Science?
3. Students’ ideas about the Nature of
Science/Physics
4. Implications for physics teaching
1.
In an experiment you should keep taking
measurements until you get two values that are the
same. That’s then the true value.
2.
If two scientists disagree about the interpretation of
data from an investigation then one (or both!) of them
must be incompetent or biased.
3.
Scientists are independent of government.
4.
Scientists should be able to tell us whether something
is completely safe (e.g. using mobile phones).
Young people’s ideas about theories
in science
‘If you set up a hypothesis not yet clearly proven, it is a theory. After
the theory is proven it will become a law’
‘It’s just a theory – they don’t know for sure’
‘Theories are guesses that haven’t been proven yet’
Students’ understandings of the nature of
scientific knowledge I
•
•
•
•
Level 1
Knowledge directly reflects reality.
The goal of science is to invent things.
Lack of distinction between the goal of understanding a phenomenon
and producing a phenomenon.
Lack of distinction between theory and evidence.
‘An experiment is when you try it and see if it works’
The goal of science is:
‘to discover new things’;
‘to find new cures for diseases’
Carey, S., Evans, R., Honda, M., Jay, E., & Unger, C. (1989). 'an experiment is when you try
and see if it works': A study of grade 7 students' understanding of the construction of
scientific knowledge. International Journal of Science Education, 11, 514-529.
Students’ understandings of the nature of
scientific knowledge II
Level 2
• Clear distinction between ideas and experiments.
• Inquiry is guided by particular ideas and questions.
• No recognition that the results of an experiment may lead to revision
of an idea.
Scientists do experiments : ‘to test to see if their idea is right’
Students’ understandings of the nature of
scientific knowledge III
Level 3
• The purpose of experiments is to test and explore ideas - if
unexpected results appear the scientist will need to modify their idea.
• Science is a cyclic, cumulative activity.
A scientist: ‘probably thinks up an idea, and then builds an
experiment out of the idea, and if he’s right or wrong he keeps
building up more questions to see, to find out even more stuff than
he knows’
‘He’d probably have to change his hypothesis a little to fit in with the
new data’
Level
Key
differentiations
Nature of
knowledge
Process of enquiry
1
No differentiation True beliefs about
of ideas and
what happens and
evidence
what works
Making
observations, doing
tests, finding
answers
2
Simple
differentiation of
ideas and
evidence
Well tested
hypotheses;
generalisations
about how or why
something works
Simple hypothesis
testing
3
Differentiation
among theories,
hypotheses and
evidence
Well tested coherent Cycles of hypothesis
theories (explanatory testing that test and
frameworks)
develop theories
(Based on Carey and Wenk, 2006)
Outline
1. What is the Nature of Science?
2. Why teaching/learning about the Nature of
Science?
3. Students’ ideas about the Nature of
Science/Physics
4. Implications for physics teaching
21st Century Science GCSE Course
We need a curriculum model for science that offers
flexibility and genuine choice to cope with the diversity of
students' interests and aspirations.
The model we propose offers all students the chance to
develop the scientific literacy that they need to play a full
part in a modern democratic society where science and
technology play a key role in shaping our lives - as active
and informed citizens. In addition, for some students –
perhaps a minority – we are producing courses which
provide the first stages of their training as a scientist, or
for a career that involves science.
http://www.21stcenturyscience.org/home/index.asp
Curriculum purposes
1.
Science education as preparation for advanced
study in science
2.
Science education to support people’s
engagement with science as citizens
21st Century Science
Twenty First Century Science offers three different GCSE
science courses for different purposes.
Science: scientific literacy for all
For all Key Stage 4 students (age 14 to 16), taking 10% of
their curriculum time and leading to one GCSE grade.
Additional science
Alongside core Science, young people can opt for one of
two Additional Science courses, also taking 10% of
curriculum time and leading to one GCSE grade:
- Additional Science
- Additional Applied
21st Century Science GCSE Course
• Module topics (e.g. Air Quality, Keeping Healthy,
Food Matters)
• Scientific Explanations
• Ideas about Science (i.e. the ‘nature of science’)
Teachers’ experiences of 21CS
We notice that the enthusiasm, the engagement level is
going up, so they’re becoming more interested in science.
We are having pupils who are staying behind to ask
questions in certain groups which wasn’t happening before
Well with our kids in particular, they love discussion and
(…) they are very good at doing it. What I would think our
teachers need is strategies on how to actually do
discussions (…) a lot of teachers are too scared to kind of
let go and just let the kids talk about stuff, and then sort of
bring them back together to find out what they think.
Teachers’ experiences of 21CS
There are two things that have happened this year that
have not happened before. The first thing is that lessons
have been completely taken over by the students asking
the questions. The second, and by far the best, thing is that
not once, not on a single occasion, not ever this year have I
had to answer the question ‘why do we have to learn this?’
(Teacher quoted in IOP Education newsletter Feb 2008)
Teachers’ experiences of 21CS
Should Physics be more elitist?
Physics is a subject that requires certain intellectual skills
that the majority of the population do not have… there
persists a strange notion that anyone and everyone should
study… physics … such a notion is patently absurd.
(Headteacher, Physics World, 2004, in an exchange with Jonathan Osbourne)
Leeds study
240 teachers; written questionnaire; open responses
End of first run through 2 year courses for 14-16 year olds
38% improved student motivation
30% improved student achievement
45% challenge of managing changes to assessment
29% difficulties with resourcing
14% difficulties with teaching nature of science
12% difficulties ‘finding’ practical work
19% ‘dumbing down’ of science curriculum
Students’ experiences of 21CS
It is a quite up to date modern course that teaches you
useful things that you can relate to like real life
situations, so you could actually use it in real life.
You remember more out of these lessons because it is
more relevant to you now, instead of just you go past
and see a sign for like genetic babies and you would
say ‘oh I know about that’
Challenges and opportunities ahead
• The curriculum is already overcrowded. How can we
possibly teach more in the science curriculum?
• Why change the science curriculum yet again?
• All this is new to me. How do I teach the nature of
science?
• I enjoy teaching about the nature of science but many of
my students resent it because it isn't on the exam.
• All this ‘discussion’ about socio-scientific issues is going
to ‘turn off’ the students who would normally choose to
study physics further, and become the physicists of the
future