Understanding the Practices of Science for Classroom Implementation

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1 Understanding the Practices of Science for Classroom Implementation Paul Numedahl, PhD 13 October 2011 National Association of Biology Teachers Conference Anaheim, CA

2 What are the practices of science? Think About

3 Practices of Science Evidence-based science explanations

4 Question to consider What are the key components of a Scientific Explanation?

5 Revisit your ideas What are the key components of a Scientific Explanation? Using your ideas, construct a scientific explanation of the following data

6 Light Intensity None (Covered) Low (Room Overhead Light) Medium (3 feet away from light source) High (1 foot away from light source) Writing an Explanation A student conducted an experiment using Bromothymol Blue to determine the effects of light intensity on the rate of photosynthesis in the leaves of Elodea. Time for Notable Color Change (minutes) No color change 15 Using the data table above, develop an explanation that describes how the amount of light intensity affects the rate of photosynthesis. 10 5

7 Evidence-based Science Explanations Components Make a claim about the problem. Provide evidence for the claim. Provide reasoning that links the evidence to the claim and to science principles. Qualities of the communication Use precise and accurate scientific language. Write clearly so that anyone interested in the explanation can understand it. Including specifically references data and observations

8 Example Evidence-based Explanation Claim The rate of photosynthesis increases when the light intensity increases. B Evidence When there is no light, there is no color change. When the light intensity is low, the color change takes longer (15 minutes) than when the light intensity is high (5 minutes). Bromothymol Blue changes color when carbon dioxide levels change. C Reasoning Photosynthesis is the process in which plants use water, carbon dioxide, and light energy from the sun to produce sugars and release oxygen as a byproduct. As the rate of photosynthesis increases, more oxygen is produced and carbon dioxide is used, therefore changing the color of the solution more quickly. The change in light intensity affected the rate of photosynthesis because the evidence showed a decrease in the amount of time it took for a color change to happen as the light intensity increased.

9 BSCS Biology: A Human Approach BSCS Biology: A Human Approach Third Edition, published by Kendall/Hunt, Copyright This program is based on work supported by the National Science Foundation under Grant No. ESI

10 Explore/Explain: Patterns of Inheritance AHA 3 Chapter 11 Male rabbits, floppy ears Female rabbits, floppy ears Males Females Number of Offspring Floppy Straight Floppy Straight Based solely on the results of this cross, What conclusions can be drawn? Male rabbits, straight ears Female rabbits, floppy ears Males Females Number of Offspring Floppy Straight Floppy Straight What overall conclusions can you draw about inheritance of straight ears verses floppy? Do you think the type of ear a rabbit is born with is affected by whether a rabbit is female or male? Explain your answer.

11 Evidence-based Science Explanations Male rabbits, floppy ears Female rabbits, floppy ears Males Females Number of Offspring Floppy Straight Floppy Straight Male rabbits, straight ears Female rabbits, floppy ears Males Females Number of Offspring Floppy Straight Floppy Straight What overall conclusions can you draw about the inheritance of straight ears versus floppy ears and how do you think the type of ear a rabbit is born with is affected by whether a rabbit is female or male? With a partner come up with a statement (claim) about the two traits (ears and sex) that is true. Support your claim by providing evidence from your examination of both genetic crosses.

12 Evidence-based Science Explanations Share your work Write your claim with supporting evidence on a piece of chart paper. Museum Walk Read each claim and the supporting evidence. Think about the validity of each claim as you read them.

13 Evidence-based Science Explanations Components Make a claim about the problem. Provide evidence for the claim. Provide reasoning that links the evidence to the claim and to science principles. Qualities of the communication Use precise and accurate scientific language. Write clearly so that anyone interested in the explanation can understand it. Including specifically references data and observations

14 What is the question that you want to answer? Constructing a Scientific Explanation List the sources used for the evidence that will be used to support your explanation. Claim(s) that you think answer the question Evidence to support your explanation Evidence that supports your claim(s) Explanation for your answer to the question = Claim + Evidence + Reasoning My claim is because (Evidence + Reasoning). Adapted from Supporting Students Construction of Scientific Explanations by Fading Scaffolds in Instructional Materials. (2006) McNeil, KL; Lizotte, DJ; Krajcik, J; & Marx, RW. The Journal of the Learning Sciences, 15(2),

15 Evidence-based Science Explanations What science principle(s) could be used to link evidence and claim? Incorporate your reasoning into your evidencebased science explanation.

16 Practices of Science Were other practices of science evident in the modified lesson? How could these practices be made more explicit?

17 Thank you for your participation!

18 To download this presentation, visit Mark Dabling Blvd Colorado Springs, Colorado E: W: P:

Cellular Respiration and Photosynthesis Virtual Lab

Cellular Respiration and Photosynthesis Virtual Lab http://glencoe.mcgraw-hill.com/sites/0078695104/student_view0/unit2/chapter8/virtual_labs.html# 1. Go to the above website. 2. Read and follow the directions