Multiple Representations And Misconceptions In Science Instructional Materials, originally presented at a high school Science Teacher Forum, January 2006.

1. You See it – But Do You Believe It? Multiple Representations and Misconceptions in Science Instructional Materials High School Science Teacher Forum for North San Diego County Teachers Dr. Larry Woolf [email_address] www.sci-ed-ga.org (click on presentations) General Atomics Presented 1/11/05 at North County Professional Development Federation

3. What do you or your students know about color?

4. Let’s see what are the primary colors according to expert sources

10. What is meant by “primary colors?”

17. Color math W W W C W – R = C

19. Color math W M W – G = M

21. Color math W Y W – B = Y

23. Color math W W – R – G – B = 0 W = R + G + B

24. Alternate model W – R – G – B = 0 W = R + G + B

25. Place a cyan film over a magenta film What color of light do you start with? What colors of light are subtracted? What color of light remains? How can you describe this mathematically? How can you describe this pictorially?

26. Color math (R +G +B) – R – G = B B

27. Now use an alternate pictorial model to show what happens:

28. Alternate pictorial model (R +G +B) -R = G +B -G (G +B) = B

29. What color results from these pair of colored film?

30. What color results from these pair of colored film?

31. What is the one big idea that determines color?

34. Color Wheel Model for Subtractive Colors Y M C What colors are between each of the subtractive primaries?

35. Color Wheel Model for Subtractive Colors R Y M B G C Now let’s deconstruct the model in terms of cyan, magenta, and yellow components

36. R Y M B G C Deconstruct the model in terms of cyan, magenta, and yellow components Now, how could you make this “real?”

37. Put them together and see what happens- Do you make a color wheel?

38. Color Wheel Model for Subtractive Colors R Y M B G C What are the limitations of this model? Does it show all the possible colors? Does this model explain how our eyes see color?

39. A more sophisticated color model: L* a* b* color space

43. From: http://www.physics.indiana.edu/~hake/ “ Interactive-engagement vs traditional methods: A six-thousand student survey of mechanics test data for introductory physics courses ” Richard R. Hake Department of Physics, Indiana University, Scientific evidence: interactive engagement is more effective than passive lecture for understanding of conceptually difficult subjects

44. Why is it hotter in the summer than the winter?

45. Let’s now watch part of the video: “ A Private Universe”

47. Are the rays from the Sun ever *indirect*? Is Earth’s orbit egg-shaped? At Earth’s surface, are the Sun’s rays parallel? Can you make a scale drawing of the Earth, Sun, and Earth-Sun distance? Does the amount of atmosphere the sunlight passes through contribute to the seasons (i.e. more atmosphere to pass through in the winter so less intense sunlight)? What do you think about these questions? Let’s see what the experts say …

48. From: A Private Universe Teacher’s Guide, p. 18 Misleading terms: “indirect rays” and “direct rays”

53. http://csep10.phys.utk.edu/astr161/lect/time/seasons.html Critically analyze this figure

54. Misleading scales and diagrams Overly distorted Sun position and elliptical orbit http://csep10.phys.utk.edu/astr161/lect/time/seasons.html Note: egg-shaped orbit. This type of diagram is common in Earth and space science texts. Even though the text of this figure states it is not to scale, we only remember the incorrect misleading image!

55. http://hea-www.harvard.edu/ECT/the_book/Chap2/Chapter2.html Critically analyze this figure

56. http://hea-www.harvard.edu/ECT/the_book/Chap2/Chapter2.html Misleading scales and diagrams Earth is larger than the Sun, the Sun emits rays in two opposite directions, all the rays are parallel, Earth is 3 diameters from the Sun

58. From GEMS: The Real Reasons for Seasons p. 92 Sun’s rays are parallel Conflicting models for the sun’s rays

59. From: “What is Light and How Do We Explain It” by Bill G. Aldridge; Scope Sequence and Coordination High School Project of NSTA, 1996 Sun’s rays are not parallel Conflicting models for the sun’s rays

63. Incorrect Explanations? According to MSNBC, NOAA, and NASA, the amount of atmosphere the sunlight passes through is a primary cause of the seasons. Is this true? From: http://www.msnbc.com/news/251727.asp

64. From: Earth Science Seventh Edition by Tarbuck and Lutgens Incorrect Explanations? According to this Earth Science textbook, the amount of atmosphere the sunlight passes through is a cause of the season: true? Does the atmosphere deplete the solar energy more in winter than summer because rays pass through more atmosphere in winter than summer? WINTER at 40 ° SUMMER at 40 °

66. Data indicate that the amount of atmosphere that sunlight passes through is not a major cause of the seasons L. Woolf, 2005, unpublished analysis The amount of atmosphere does not substantially change the amount of solar energy striking the ground.

67. More complete data that indicate that the amount of atmosphere that sunlight passes through is not a major cause of the seasons L. Woolf, 2005, unpublished analysis The amount of atmosphere does not substantially change the amount of solar energy striking the ground.