1. Major Outcomes of Science Instruction
Proficiencies:
Conceptual knowledge & understanding in science
Abilities to carry out scientific inquiries
Understandings about the nature of science & scientific inquiry

2. Major Outcomes of Science Instruction
Proficiencies:
Conceptual knowledge & understanding in science
Facts, concepts, principles or laws, models, theories, explanations, hypotheses
Abilities to carry out scientific inquiries
Understandings about the nature of science & scientific inquiry
Q: How does Proficiency 1, Conceptual Knowledge and Understanding in Science, relate to the Next Generation Science Standards?
A: This is part of NGSS Disciplinary Core Ideas:
“the framework focuses on a limited number of core ideas in science and engineering both within and across the disciplines.”
NRC, A Framework for K-12 Science Education, p. 11
as well as NGSS Crosscutting Concepts:
“concepts common to so many areas of science and engineering.”
NRC, A Framework for K-12 Science Education, p. 85

3. Major Outcomes of Science Instruction
Proficiencies:
Conceptual knowledge & understanding in science
Facts, concepts, principles or laws, models, theories, explanations, hypotheses
Abilities to carry out scientific inquiries
Understandings about the nature of science & scientific inquiry
“Is it a Theory?” probe
(to hand in)

4. Is It a Theory?
1. Select the statements you think best apply to scientific theories.
Theories are supported by evidence
Theories are “hunches” scientists have
Theories can include personal beliefs or opinions
Theories have been tested many times
Theories are incomplete, temporary ideas
A theory never changes
Theories are inferred explanations, supported by observations
A scientific law has been proven and a theory has not
Theories are used to make predictions
Laws are more important to science than theories
2. Examine the statements you selected. Describe what a theory in science means to you.
Is it a
theory?
Keeley, P., Eberle, F., & Dorsey, C. (2008). Uncovering Student Ideas in Science (Vol. 3): Another 25
Formative Assessment Probes. Arlington, VA: National Science Teachers Association Press. ©

5. Scientific Laws, Theories, & Hypotheses
“Ladder of Confidence”
Scope
This is one framework of looking at these definitions (historical). I don’t like this one.
Laws (or Principles)
Theories
Increasing
Confidence
Hypotheses
Foundation of Evidence
Scotchmoor, J. (Ed.) (2002). Dinosaurs: The science behind the stories. Alexandria, VA: American Geological Institute.

6. Scientific Laws, Theories, & Hypotheses
Scope
Examples:
Birds are direct descendents of dinosaurs
A ball goes flat outside in the winter
because it’s cold outside
Increasing
Confidence
Hypotheses – Formal expressions of ideas; small scale,
– Sometimes preliminary, sometimes strongly
supported by data
– The day-to-day currency of science
Foundation of Evidence

7. Scientific Laws, Theories, & Hypotheses
Scope
Examples:
Einstein’s Theory of Relativity – postulates
that the speed of light is the upper limit for
the velocity of a particle.
Darwin’s Theory of Natural Selection –
variation, heritability, selection
used to
form
hypotheses
Theories – Explanation of some aspect of the natural
world, based on extensive reasoning, testing,
and refinement.
– Broad & encompassing, have stood the test
of time.
– Describe why things happen.
Increasing
Confidence
Foundation of Evidence

8. Scientific Laws, Theories, & Hypotheses
Scope
Laws (or Principles) EXTREMELY RARE!
– Based on many observations of natural
phenomena
– Universal principles that apply in all cases.
– Describe what happens, but not why.
Examples:
Newton’s 2nd Law of Motion, F=ma
Law of Superposition, Sedimentary layers
are deposited in a time sequence, with the
oldest on bottom and youngest on top.
Increasing
Confidence
Foundation of Evidence

9. Scientific Laws, Theories, & Hypotheses
Scope
Laws (or Principles)
Summary:
“Theory” has a specific meaning in science
Knowledge does not move up the ladder,
the ladder represents breadth of scope
and confidence in its validity
All forms of scientific knowledge rest on
a foundation of evidence derived from data
Theories
Increasing
Confidence
Hypotheses
Foundation of Evidence

10. A better definition Hypothesis Law Theory
A prediction about how natural phenomena will behave
States WHAT happens
“What goes up, must come down”
States WHY something happens
Darwin’s theory of natural selection
None of these is “better” than another- they are just different.

11. Is It a Theory?
1. Select the statements you think best apply to scientific theories.
Theories are supported by evidence
Theories are “hunches” scientists have
Theories can include personal beliefs or opinions
Theories have been tested many times
Theories are incomplete, temporary ideas
A theory never changes
Theories are inferred explanations, supported by observations
A scientific law has been proven and a theory has not
Theories are used to make predictions
Laws are more important to science than theories
2. Examine the statements you selected. Describe what a theory in science means to you.
Do not change what you originally wrote but, in a new paragraph, identify & describe:
What was correct about your original response
What was incorrect about your original response
How you would revise your response now, if at all
Is it a
theory?
Keeley, P., Eberle, F., & Dorsey, C. (2008). Uncovering Student Ideas in Science (Vol. 3): Another 25
Formative Assessment Probes. Arlington, VA: National Science Teachers Association Press. ©

12. Is It a Theory?
1. Select the statements you think best apply to scientific theories.
Theories are supported by evidence
Theories are “hunches” scientists have
Theories can include personal beliefs or opinions
Theories have been tested many times
Theories are incomplete, temporary ideas
A theory never changes
Theories are inferred explanations, supported by observations
A scientific law has been proven and a theory has not
Theories are used to make predictions
Laws are more important to science than theories
2. Examine the statements you selected. Describe what a theory in science means to you.
Is it a
theory?
Keeley, P., Eberle, F., & Dorsey, C. (2008). Uncovering Student Ideas in Science (Vol. 3): Another 25
Formative Assessment Probes. Arlington, VA: National Science Teachers Association Press. ©

13. Leonardo’s “Tree Theory”
The cross-sectional area of a tree’s trunk is approximately equal to the sum of the cross-sectional areas of its limbs at every stage of its height.
Can we test this idea?
What is(are) the formula(e)?
AT= AA + AB+ … + An
A=π r 2
What could we measure on the tree (without cutting trunk or limbs)?
r = d/2
d = c/π
Richter, J.P., ed. (1939). The Literary Works of Leonardo da Vinci, vol. 1, plate 27. Oxford University Press: London.

14. Leonardo’s “Tree Theory”
The cross-sectional area of a tree’s trunk is approximately equal to the sum of the cross-sectional areas of its limbs at every stage of its height.
But first,
is this a “theory?” Why/why not?
NO - it doesn’t explain why or how
Richter, J.P., ed. (1939). The Literary Works of Leonardo da Vinci, vol. 1, plate 27. Oxford University Press: London.

15. Explaining Leonardo’s Area-Preserving Rule
Most botanists thought these proportions resulted in the most efficient way to transport sap to the leaves (a “vascular” explanation). ← the “why”
To test this explanation, Aratsu (1998) measured diameters of branches where one branch had split into two, forming a Y, on 10 species of trees with different vascular structures.
White Oak, Red Oak, Black Oak, American Elm, Black Walnut, Sugar Maple, American Beech, Tuliptree, White Pine, Red Cedar
What would this explanation predict for trees with different vascular structures?
If these proportions are the result of the most efficient vascular structure,
And we measure & calculate these proportions for trees having different vascular structures,
Then we should find that trees with different vascular structures have different proportions; i.e., this rule would only hold for trees having the most efficient of the vascular structures. If
And
Then
Aratsu, R. (1998). Leonardo was wise: Trees conserve cross-sectional area despite vessel structure. Journal of Young Investigators, 1. Available:

16. Explaining Leonardo’s Area-Preserving Rule
Most botanists thought these proportions resulted in the most efficient way to transport sap to the leaves (a “vascular” explanation). ← the “why”
To test this explanation, Aratsu (1998) measured diameters of branches where one branch had split into two, forming a Y, on 10 species of trees with different vascular structures.
White Oak, Red Oak, Black Oak, American Elm, Black Walnut, Sugar Maple, American Beech, Tuliptree, White Pine, Red Cedar
Aratsu’s findings:
“From the results of this study, it appears that the dimensions of the ten species I observed nearly obey Leonardo's rule and preserve area across every branching.
“The mystery that remains is the explanation for this phenomenon.
“The vascular explanations that have been presented are not adequate to explain my findings, so we must look to more universal ecological pressures to which the trees could be responding.”
Aratsu, R. (1998). Leonardo was wise: Trees conserve cross-sectional area despite vessel structure. Journal of Young Investigators, 1. Available:

17. Explaining Leonardo’s Area-Preserving Rule
Eloy (2011) proposed these proportions protect trees from wind damage
He used analytic and numeric models to computer design the lightest possible tree structure that could still withstand wind
The models fit Leonardo’s formula
What does this mean for the
“Tree Theory?”
Taking it to the Classroom
Fol 78v-79r - Diagrammatic drawing of the growth of trees. Photo RMN - © René-Gabriel Ojéda. Available:
Eloy, C. (2011). Leonardo's rule, self-similarity, and wind-induced stresses in trees. Physics Review Letters, 107,

18. Photo of bear hugging tree
File photo of black bear in tree. (2012, September 7). Bozeman Daily Chronicle, p. A1.
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19. Teaching Proficiency 1, Conceptual knowledge and understanding in science
Elementary
Engage in inquiry skills and activities to develop conceptual knowledge and understanding: asking questions and seeking answers, collecting, counting, measuring, observing, organizing, discussing, etc.
Precursors to understanding how science relies on evidence
Middle School
Begin to deal with the changing nature of scientific knowledge
Scientific meaning of theory
Theories (and their development) connected with content
Leonardo’s Area Preserving Rule (~ 8th grade)
Louis Pasteur