Evaluating Scientific Claims, Cornelia Harris, Cary Institute of Ecosystem Studies. Presented at Teaching the Hudson Valley's 2012 summer institute.

1. Evaluating Scientific
Claims
A Method for Exploring Controversial
Environmental Questions

2. Consider Two Sets of Information
Evidence 1
Evidence 2
Data from the World
Conservation Union Polar
Bear Specialist Group
(2010) about 19 separate
populations of polar
bears.

3. Consider this scientific question: Should
hydrofracking be allowed in New York State?
Claim: The amount of wastewater produced will be
minimal.
Yes! Evidence:
The amount of wastewater produced in New York will be
very small. For example, the wastewater discharged from
all offshore (US) drilling operations is around 175 million
barrels per year. In order to reach that amount in
Marcellus drilling, all of the wastewater produced by
22,000 wells (10 times the amount predicted by the DEC to
be drilled in any given year) would need to be discharged.
NO! Evidence:
Even though there is not much wastewater
produced, NYS has much less water than the Gulf
of Mexico so the dilution and dispersal of the
chemicals will not be as easy.

4. Mini Unit Overview
• Students are introduced to…
– Scientific arguments (claims, evidence, reasoning)
– Scientific questions
– Socioscientific issues
– Ways scientists evaluate arguments
Using Science In Decision-Making

5. Mini Unit Overview
• Contexts: Template format provides ability to adapt
to any socioscientific issue (e.g., place-based issue)
• Grades: Middle to High
• Time: 3 to 4 class sessions
– with longer or repeat options
• Materials Needed: Teacher Guide, Student
Handouts, Video Projection, Articles for Students
– Materials available online at:
http://edr1.educ.msu.edu/environmentallit/publicsite/h
tml/ci_tm.html
Using Science In Decision-Making

6. Learning Objectives
• Understand that we use scientific arguments to
answer scientific questions
• Be able to distinguish between questions that
can/cannot be addressed by science
• Understand that a scientific argument includes…
– A claim
– Evidence
– Reasoning
Using Science In Decision-Making

7. Learning Objectives (cont.)
• Understand that in science we use specific
criteria (e.g., replication, peer review, etc.) to
evaluate scientific arguments
• Be able to evaluate credibility of sources through
relying on at least 1 scientific criterion
• Understand science is just 1 lens for considering
socioscientific issues
Using Science In Decision-Making

8. Mini Unit Overview
Activity
1 Intro Scientific Argumentation (video context)
2 Students develop criteria to evaluate arguments
(article context)
3 Intro/consider evaluation criteria of scientific
communities
4 Why should we care about scientific arguments?
Optional Application Activities
Using Science In Decision-Making

9. Activity One
• Students introduced to brief definitions of…
– Scientific (and non-scientific) questions
– Scientific arguments (CER)
– Socioscientific issue
• Students watch short video and answer
questions to consider terms in context
Using Science In Decision-Making

10. What is a Scientific Argument and how is it different
from arguments people have in everyday life?
A scientific argument is used to answer a scientific
question, and includes a claim, evidence, and reasoning.
Characteristics of Characteristics of
Scientific Arguments Everyday Arguments
• Your opinion is important
• Evidence to back up a claim
• Feelings/emotions are
• Argument can be tested important
• Logical • Personal bias
• Based on facts • Attacking a person and not
• Supported by the evidence
data, observations, evidenc • Popular opinion influences
e argument

11. Before we jump into the video…
let’s talk about your experience teaching
about claims, evidence, and reasoning.

12. Example: Day and Night
Claim Evidence Reasoning
Day and night are caused A photo taken of the Pole Either all the stars are
by a spinning Earth. Star with a long exposure rotating around the Pole
shows all the stars going Star (and Earth is not
round the pole star. spinning) or the ground on
which the camera sits is
Movement of Foucault’s turning.
Pendulum is another piece
of evidence.

13. Current is Conserved
Claim Evidence Reasoning
Current is conserved in a When you measure the If current was “used up” in
simple circuit. current in a simple circuit the circuit, then the
before and after a bulb with ammeter would read a
an ammeter, both readings lower current in the wire
are identical. after the bulb compared
with before the bulb.

14. Plants  CO2 in O2 Out
Claim Evidence Reasoning
Plants take in carbon Oxygen: If you collect gas in Pure oxygen is more
dioxide and give out a sealed jar of elodea (a flammable than air, so
oxygen during plant) illuminated by light, there is a higher
photosynthesis. the gas will relight a glowing concentration of oxygen in
wood splint. the sealed jar with the
plant that has been
More recently oxygen and illuminated.
carbon dioxide probes have
become available for
conducting experiments with
plants in the classroom

15. Now You Try --- Pangaea
• Claim: About 250 million years ago, land on
Earth consisted of one supercontinent.
• Use information in the graphic on the next slide
to describe some evidence and reasoning for
the claim.

16. Describe Evidence & Reasoning
Colored dots show where fossils of land mammals and plants that lived 250
million years ago have been found.

17. Hygiene Hypothesis
NOW TO THE VIDEO!
http://www.pbs.org/wgbh/evolution/library/10/4/l_104_07.html

18. What scientific argument did Dr. von
Mutius (and the narrator) make?
What was her claim?
What was her evidence?
What was her reasoning?

19. • What socioscientific issue or issues is this
scientific argument relevant to?
• If you wanted to decide what ought to be done
about this socioscientific issue, what other
scientific questions in addition to the one in
the video would you want to consider?
• What non-scientific questions would you want
to consider?

20. Activity Two
• Students read articles (jigsaw possible) providing
multiple arguments re a socioscientific issue
• Students identify CER for each source
• Students develop and apply own criteria for
evaluating strength of arguments
Using Science In Decision-Making

21. Socioscientific Issues for Today
• How can we increase carbon
storage in our forests?
• Are polar bears an endangered
species?
Using Science In Decision-Making

22. What’s the
Argument
Here?

23. What Makes for a Strong or Weak
Scientific Argument?
How can you tell whether a scientific argument is strong or weak? Discuss with your group
and list criteria (factors) below that you can think of that you would use to judge the
strength or weakness of a scientific argument.
Criteria (Factors) for Evaluating How Strong or Weak a Scientific Argument Is:

24. Evaluating Arguments in Articles
Criterion Strength (S), Explain why the scientific argument is strong or
Neutral (N), or
(Factor) Weakness (W) weak for each criterion you list.

25. What’s Your Opinion?
• What is your opinion about what should be
done about this issue and why?
• Is there anything that you could do to impact
this issue? What are some things you could do
and how might they impact the issue?

26. Activity Three
• Students introduced to criteria scientists use
• Focus is on intro/awareness, not depth
• Students compare own and scientific criteria
• Students revisit evaluations of sources using
scientific criteria
Using Science In Decision-Making

27. Activity Three
Some Criteria Scientists Use
• Scientific evidence
• Sample size
• Appropriate measures
• Rigorous data collection
• Replication
• Underlying scientific concept
• Consensus
• Peer review
• Bias
Using Science In Decision-Making

28. Activity Four
• What are some socioscientific issues that you
know about and/or that are important to you?
• For one issue you’ve identified, what are some
scientific questions that investigating could help
people understand the issue better?
Using Science In Decision-Making

29. Activity Four
• Can answers to scientific questions provide us
with all the information we need to make a good
decision about what to do about a socioscientific
issue? Why or why not?
• If not, what other information would be needed?
Using Science In Decision-Making

30. Activity Four
• Is there generally a right and wrong answer to
what should be done about a socioscientific
issue? Why or why not?
• If two people had the same exact information
available to them about a socioscientific issue,
could they make different decisions with both
being considered informed decisions? Why or
why not?
Using Science In Decision-Making

31. Activity Four
• Can all scientific questions be answered with
100% certainty? If not, can investigating these
questions still help us to understand issues
better, or is science only useful if it provides
definite answers?
• Has this set of activities changed the way you’ll
consider scientific arguments in the future? If
yes, how will what you do be different from what
you’ve done before?
Using Science In Decision-Making

32. Implementing this Unit
• Materials are available on the MSU
Environmental Literacy website including:
– Teacher Guide
– Student Handouts
– Topic Packages with articles and teacher notes for
each topic
– Teacher Feedback Form
• If you’re interested in the research portion of
this project, please contact me