Major Outcomes of Science Instruction Proficiencies: 1.Conceptual knowledge & understanding in science 2.Abilities to carry out scientific inquiries 3.Understandings

Major Outcomes of Science Instruction

Proficiencies: 1. Conceptual knowledge & understanding in science2. Abilities to carry out scientific inquiries3. Understandings about the nature of science & scientific inquiry


Proficiencies: 1. Conceptual knowledge & understanding in science

• Facts, concepts, principles or laws, models, theories, explanations, hypotheses

2. Abilities to carry out scientific inquiries3. 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


Proficiencies: 1. Conceptual knowledge & understanding in science

• Facts, concepts, principles or laws, models, theories, explanations, hypotheses

2. Abilities to carry out scientific inquiries3. Understandings about the nature of science & scientific inquiry

“Is it a Theory?” probe (to hand in)

Is It a Theory?1. Select the statements you think best apply to scientific theories.

A. Theories are supported by evidence

B. Theories are “hunches” scientists have

C. Theories can include personal beliefs or opinions

D. Theories have been tested many times

E. Theories are incomplete, temporary ideas

F. A theory never changes

G. Theories are inferred explanations, supported by observations

H. A scientific law has been proven and a theory has not

I. Theories are used to make predictions

J. 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 25Formative Assessment Probes. Arlington, VA: National Science Teachers Association Press. ©

Scientific Laws, Theories, & Hypotheses “Ladder of Confidence”

Laws (or Principles)

Theories

Hypotheses

Increasing Confidence

Scope

Foundation of Evidence

Scotchmoor, J. (Ed.) (2002). Dinosaurs: The science behind the stories. Alexandria, VA: American Geological Institute.

This is one framework of looking at these definitions (historical). I don’t like this one.

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


Hypotheses – Formal expressions of ideas; small scale, – Sometimes preliminary, sometimes strongly supported by data – The day-to-day currency of science



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.


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


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.


Scope


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.


Laws (or Principles)

Theories

Hypotheses


Scope


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

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. http://undsci.berkeley.edu/article/0_0_0/howscienceworks_19

http://undsci.berkeley.edu/article/0_0_0/howscienceworks_19

http://undsci.berkeley.edu/article/0_0_0/howscienceworks_19

Is It a Theory?


Is it a

theory?

1. Select the statements you think best apply to scientific theories.












Do not change what you originally wrote but, in a new paragraph, identify & describe:1) What was correct about your

original response2) What was incorrect about your

original response3) How you would revise your

response now, if at all

Is It a Theory?1. Select the statements you think best apply to scientific theories.













Is it a

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.

Leonardo’s “Tree Theory”

Richter, J.P., ed. (1939). The Literary Works of Leonardo da Vinci, vol. 1, plate 27. Oxford University Press: London.

Can we test this idea?

What could we measure on the tree (without cutting trunk or limbs)?

What is(are) the formula(e)?

A=π r2AT= AA + AB+ … + An

r = d/2d = c/

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.

Leonardo’s “Tree Theory”

Richter, J.P., ed. (1939). The Literary Works of Leonardo da Vinci, vol. 1, plate 27. Oxford University Press: London.

But first,is this a “theory?” Why/why not?

NO - it doesn’t explain why or how

Explaining Leonardo’s Area-Preserving Rule

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.

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.

Aratsu, R. (1998). Leonardo was wise: Trees conserve cross-sectional area despite vessel structure. Journal of Young Investigators, 1. Available: http://www.jyi.org/volumes/volume1/issue1/articles/aratsu.html

White Oak, Red Oak, Black Oak, American Elm, Black Walnut,

Sugar Maple, American Beech, Tuliptree, White Pine, Red Cedar

If

And

Then


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.”

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.

Aratsu, R. (1998). Leonardo was wise: Trees conserve cross-sectional area despite vessel structure. Journal of Young Investigators, 1. Available: http://www.jyi.org/volumes/volume1/issue1/articles/aratsu.html

White Oak, Red Oak, Black Oak, American Elm, Black Walnut,

Sugar Maple, American Beech, Tuliptree, White Pine, Red Cedar

• 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


Fol 78v-79r - Diagrammatic drawing of the growth of trees. Photo RMN - © René-Gabriel Ojéda. Available: http://www.universalleonardo.org/trail.php?trail=545

What does this mean for the “Tree Theory?”

Eloy, C. (2011). Leonardo's rule, self-similarity, and wind-induced stresses in trees. Physics Review Letters, 107, 258101.

Taking it to the Classroom

http://www.photo.rmn.fr/cf/htm/home.aspx

File photo of black bear in tree. (2012, September 7). Bozeman Daily Chronicle, p. A1.

Photo of bear hugging tree

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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

Documents

Major Outcomes of Science Instruction Proficiencies: 1.Conceptual knowledge & understanding in science 2.Abilities to carry out scientific inquiries 3.Understandings