Knowing Your Audience:

Transcription

1 Knowing Your Audience: Astronomy Misconceptions by the Public Ka Chun Yu Curator of Space Science Denver Museum of Nature & Science 2001 Colorado Blvd. Denver, CO (DMNS) 1 / 36

2 Introduction What are misconceptions? Alternate conceptions, preconceptions : deep-seated beliefs incompatible with accepted scientific knowledge. What is the purpose of this talk? (DMNS) 2 / 36

3 Introduction Difficulty of Learning Astronomy Physical systems cannot be experienced directly Mental model construction required Erroneous mental models are hard to change (constructivist theory, A Private Universe [1987]) Underlying principles also difficult to learn (DMNS) 3 / 36

4 Introduction Shape of the Earth (K 5) From Nussbaum 1985, Baxter 1989, Vosniadou 1991, Sneider et al (DMNS) 4 / 36

5 Constructivism Theories of Education Positivism: science is absolute knowledge independent of humans Science knowledge absolute, logical Science education should be logical and structured Transmissive lectures Students are tabula rasa Constructivism: Prior knowledge of learners Prior experience of learners Science knowledge is constructed Learning is an ongoing adaptive process Learner is actively engaged, not passive (DMNS) 5 / 36

6 Constructivism Astronomical Misconceptions Some classes of misconceptions: Lunar phases (Kuethe 1963, Ault 1984, Jones et al. 1987, Treagust 1988, Baster 1989, Vosniadou 1991, Sadler 1998) Seasons (Duit 2002, Bailey & Slater 2003) Orbits (Dunlop 2000, Sadler 1992) Scale of the Solar System (Sadler 1992) The Big Bang (Prather et al. 2002) (DMNS) 6 / 36

7 Constructivism Fundamental Science Misconceptions Driver et al. 1994: Making Sense of Secondary Science: Research into Children s Ideas Life: Living Things Nutrition Growth Responding to Environment Reproduction and Inheritance Microbes Ecosystem Materials and their properties: Materials Solids, Liquids, and Gases Chemical Change Particles Water Air Rocks Physical processes: Electricity Magnetism Light Sound Heating Energy Forces Horizontal Motion Gravity Earth in Space (DMNS) 7 / 36

8 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 8 / 36

9 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 8 / 36

10 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 8 / 36

11 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 8 / 36

12 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 9 / 36

13 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science Children know: When water disappears from a wet thing, it disappears into/becomes air Children are taught: Air consists of oxygen and other gases Water consists of oxygen and hydrogen Synthesis: Evaporating water turns into oxygen and hydrogen gas (DMNS) 10 / 36

14 Constructivism Ideas about Light (ages 11-14) What is light? Light as a source (light bulb, sun) Light as a state (when it is bright) Light as a distinct entity Movement of light Not explicitly accepted even though spoken as such No propagation time unless for great distances Existence of light Light does not exist, unless extremely intense E.g., a piece of paper does not reflect light, unlike a mirror Conservation Light can disappear without interacting with matter: when too weak to be perceived Light can be intensified, e.g., with magnifying glass (DMNS) 11 / 36

15 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 12 / 36

16 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 12 / 36

17 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 12 / 36

18 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 12 / 36

19 Constructivism Osborne & Freyberg 1985: Learning in Science: The Implications of Chidren s Science (DMNS) 12 / 36

20 Constructivism Forces and Motion Forces have to do with living things Constant motion requires constant force Amount of motion is proportional to amount of force There is no force on a body if it is not moving A force acts in the direction of motion of a body (DMNS) 13 / 36

21 Gravity Constructivism Gravity is related to air pressing down Earth s spin and magnetism related to gravity Weight Weight not related to gravity Gravity affects only heavy things Water Less or no gravity in water Gravity acts upwards Gravity acts only on things above water, e.g., one s head Falling Objects fall if not held up Heavier objects fall faster Gravity present only when object is falling Thrown balls have force counteracting gravity until it runs out Gravity in Space Gravity associated only with the Earth, and/or with air Gravity needs medium No gravity on Moon and/or some of the planets (DMNS) 14 / 36

22 Day and Night Constructivism Baxter 1989 Sun hides, goes to sleep, goes underground, turns off, goes behind a tree, goes behind a hill Covering of the Sun Clouds the Moon the night, dark, or the atmosphere Astronomical movements Sun goes around Earth once a day Earth goes around Sun once a day Sun goes up and down Rotation of the Earth once a day (DMNS) 15 / 36

23 Constructivism Earth, Moon, and the Sun Models Earth-centered (DMNS) 16 / 36

24 Constructivism Earth, Moon, and the Sun Models Earth-centered Spinning Earth-centered (DMNS) 16 / 36

25 Constructivism Earth, Moon, and the Sun Models Earth-centered Spinning Earth-centered Earth-centered, orbiting Sun & Moon (DMNS) 16 / 36

26 Constructivism Earth, Moon, and the Sun Models Earth-centered Spinning Earth-centered Earth-centered, orbiting Sun & Moon Sun-centered, orbiting Earth and/or Moon (DMNS) 16 / 36

27 Constructivism Earth, Moon, and the Sun Models Earth-centered Spinning Earth-centered Earth-centered, orbiting Sun & Moon Sun-centered, orbiting Earth and/or Moon Sun-centered, orbiting Earth which is orbited by Moon (DMNS) 16 / 36

28 Constructivism Lunar Phases (K 16+) From Trundle et al Clouds covering Moon (DMNS) 17 / 36

29 Constructivism Lunar Phases (K 16+) From Trundle et al Clouds covering Moon Other planets cast shadow (DMNS) 17 / 36

30 Constructivism Lunar Phases (K 16+) From Trundle et al Clouds covering Moon Other planets cast shadow Shadow of the Sun (DMNS) 17 / 36

31 Constructivism Lunar Phases (K 16+) From Trundle et al Clouds covering Moon Other planets cast shadow Shadow of the Sun Shadowing by the Earth (DMNS) 17 / 36

32 The Moon Constructivism Lunar Phases Clouds cover part of the Moon Planets cast shadows on the Moon Shadow of the Sun on the Moon Shadow of the Earth on the Moon Part of the illuminated Moon is visible from Earth Other common ideas from general population about the Moon Phases are due to shadow of the Earth Moon is up only at night Moon doesn t rotate A Quarter Moon shows a quarter of the Moon More at (DMNS) 18 / 36

33 Constructivism Direct Instruction: Birds-Eye View (DMNS) 19 / 36

34 Constructivism Constructivist Learning Field observations: where is the Moon? (Elementary Science Study 1968, GEMS 1998, Project Aries 2000; Dai 1991) (DMNS) 20 / 36

35 Constructivism Constructivist Learning Field observations: where is the Moon? (Elementary Science Study 1968, GEMS 1998, Project Aries 2000; Dai 1991) (DMNS) 20 / 36

36 Constructivism Constructivist Learning Field observations: where is the Moon? (Elementary Science Study 1968, GEMS 1998, Project Aries 2000; Dai 1991) Physical models of Earth/Sun/Moon Kinesthetic astronomy: acting out Earth/Sun/Moon (DMNS) 20 / 36

37 (DMNS) 21 / 36

38 (Sadler 1992) (DMNS) 21 / 36

39 (Sadler 1992) (DMNS) 21 / 36

40 (DMNS) 21 / 36

41 (Sadler 1992) (DMNS) 21 / 36

42 (Sadler 1992) (DMNS) 21 / 36

43 (DMNS) 22 / 36

44 (DMNS) 22 / 36

45 (DMNS) 22 / 36

46 What can you tell me about the shapes of planetary orbits? N % Typical Answers Elliptical 74 66% oval, oblong, not a perfect circle, egg-shaped Circular 22 20% Elliptical+Circular 5 4% circular orbits close in, elliptical further out; elliptical for planets, circular for moons Indeterminate idea 11 10% From oral interviews of 100+ undergraduate students at Metropolitan State College at Denver Students had signed up for introductory astronomy, but had yet to receive any instruction (DMNS) 23 / 36

47 (Bennett, Donahue, Schneider, & Voit 2007) (DMNS) 24 / 36

48 (Bennett, Donahue, Schneider, & Voit 2007) (DMNS) 24 / 36

49 (Bennett, Donahue, Schneider, & Voit 2007) (DMNS) 24 / 36

50 2D vs. 3D Learning Much of traditional classroom instruction not helpful (2D pictures, charts, slides, written descriptions) Teaching one topic may lead to reinforcement of misconceptions in another topic One solution: Use computer-based 3D modeling and visualizations (DMNS) 25 / 36

51 2D vs. 3D Learning Modern astronomy visualization software like that for the Orbits Interactive (also SCISS s Uniview running in the Gates Planetarium) now show easily: Multiple frames of reference Exocentric and egocentric viewpoints Range of size scales Time-variation (DMNS) 26 / 36

52 Explaining Seasons: Motions of the Earth 1 Rotation of the earth on its axis every 24 hours produces night-and-day cycle. This makes it seem as though sun, moon, and stars are orbiting around the earth once a day. 2 The earth is one of several planets that orbit the sun, and the moon orbits around the earth. 3 A number of planets of very different size, composition and surface features move around the sun in nearly circular orbits. 4 The axis of the Earth s rotation is tilted relative to the plane of the Earth s yearly orbit around the sun. As the Earth orbits the sun, the axis remains pointed to the same place in space. (DMNS) 27 / 36

53 Explaining Seasons: Light Warming Objects 1 The sun warms the land, air, and water. 2 A warmer object can warm a cooler one by contact or at a distance. 3 Light and other electromagnetic waves can warm objects. How much an object s temperature increases depends on how intense the light striking its surface is, how long it shines on the object, and how much of the light is absorbed. 4 The intensity of the sunlight striking a place on the surface of the Earth varies depending on what time of day it is, what time of year it is, and on how far north or south of the equator the place is. (DMNS) 28 / 36

54 Explaining Seasons: Variations of Temperature 1 The temperature and amount of rain (or snow) tend to be high, low, or medium in the same months every year. 2 The temperature of any location on the Earth s surface tends to rise and fall in a somewhat predictable pat ern over the course of a day. 3 The temperature of any location on the Earth s surface tends to rise and fall in a somewhat predictable cycle over the course of a year. 4 The yearly temperature cycle of a location depends on how far north or south of the equator it is, how high it is, and how near to oceans it is. (DMNS) 29 / 36

55 Explaining Seasons 1 The difference in how much of the day is daytime and how much is nighttime at a place on the surface of the Earth depends upon where the Earth is in its yearly orbit around the sun and how far the place is from the equator. 2 Because the Earth is a sphere, at any particular time, light from the sun strikes different parts of the Earth at different angles and therefore the intensity of light striking the surface of the Earth is different in different places. 3 The intensity of sunlight striking a place on the surface of the Earth depends upon where the Earth is in its yearly orbit around the sun and how far the place is from the equator. 4 The seasonal variations in temperatures at different places on the surface of the Earth are explained by the differential heating of the Earth s surface as it rotates on an axis that is tilted relative to the plane of the Earth s orbit around the sun. (DMNS) 30 / 36

56 (DMNS) 31 / 36

57 Teaching Strategies The most important single factor influencing learning is what the learner already knows; ascertain this and teach him accordingly. Ausubel, 1968, Educational Psychology, e.g., Find out what the learner already knows: pre-conceptions, misconceptions, alternative conceptions Design curriculum to address these alternate viewpoints Constructivist approaches seem to have better success rates than direct instruction. What exactly do we teach? (DMNS) 32 / 36

58 National Science Education Standards (National Research Council 1996) Grades K 4, pp. 130, 134 By observing the day and night sky regularly, children in grades K 4 will learn to identify sequences of changes and to look for patterns in these changes. As they observe changes, such as the movement of an object s shadow during the course of a day, and the positions of the sun and moon, they will find the patterns in these movements. They can draw the moon s shape for each evening on a calendar and then determine the pattern in the shapes over several weeks. These understandings should be confined to observations, descriptions, and finding patterns. Attempting to extend this understanding into explanations using models will be limited by the inability of young children to understand that the earth is approximately spherical.... (DMNS) 33 / 36

59 National Science Education Standards (National Research Council 1996) Grades 5 8, p. 159 The understanding that students gain from their observations in grades K 4 provides the motivation and the basis from which they can begin to construct a model that explains the visual and physical relationships among Earth, Sun, Moon and the solar system.... By grades 5 8, students have a clear notion about gravity, the shape of the earth, and the relative positions of the earth, sun, and moon. Nevertheless, more than half of the students will not be able to use these models to explain the phases of the moon, and correct explanations for the seasons will be even more difficult to achieve. (DMNS) 34 / 36

60 What to do... Don t ignore visitor s language. Ask questions! For your language... Be careful with scientific language. Be careful with everyday language. Confront them with new knowledge. How much time do you focus on getting one topic right? Concentrating more on one subject means less time for other things. What is the balance between inspiring vs. teaching? (DMNS) 35 / 36