The familiar adage "seeing is believing" implies that children will recall a particular phenomenon if they had the experience of seeing it with their own eyes. If this were true, then most children would believe that you could see the Moon in both daytime and at night. However, when children are asked, "Can you see the Moon in the daytime?" many will say "no," even though they have actually seen the Moon many times in the morning or afternoon sky. The formative assessment probe, "Objects in the Sky," (Figure 1) shows how persistent the belief is among elementary-age children that the Moon can only be seen in the nighttime (Keeley, Eberle, and Tugel 2007).
Understanding where the Moon is located at different times of the day and its changing appearance as viewed from Earth are important goals for learning. In the early elementary grades, the Benchmarks for Science Literacy state that by the end of second grade, students should know that "the Sun can be seen only in the daytime, but the Moon can be seen sometimes at night and sometimes during the day. The Sun, Moon, and stars all appear to move slowly across the sky" (AAAS 2009). The newly released A Framework for K-12 Science Education (NRC 2011) states that by the end of second grade, students should understand that "Patterns of the motion of the Sun, Moon, and stars in the sky can be observed, described, and predicted." Building on this earlier idea, by the end of fifth grade, students should understand, "The orbits of Earth around the Sun and of the Moon around Earth, together with the rotation of Earth about an axis between its North and South poles, cause observable patterns. These include day and night; daily and seasonal changes in the length and direction of shadows; phases of the Moon; and different positions of the Sun, Moon, and stars at different times of the day, month, and year."
To achieve an understanding of these important learning goals, elementary students should have the opportunity to observe the position and phases of the Moon in both the daytime and nighttime sky and discover the cyclic pattern of Moon phases by analyzing their recorded observations. This experience is one of several critical prerequisites to constructing an explanation for the phases of the Moon. Before students engage in monthly observations to discover the pattern of Moon phases, consider using a probe such as "Objects in the Sky" to find out whether students recognize that the Moon can be seen in the daytime.
With Their Own Eyes
Parts of this probe are based on research conducted on children's ideas about the Moon. Vosniadou and Brewer (1994) found that many young children believe that the Moon is only visible at night and the occurrence of the Moon in the sky is associated with nighttime. Some students will even attribute the appearance of the Moon as a causal factor for night. Research has also revealed that some students believe the Moon rises straight up in the evening, stays at the top of the sky throughout the night, and then sets straight down (Plummer 2009). When children are asked why they think the Moon is only visible at night, they often explain their thinking using this "up-down rule" and may even confuse it with the rising and setting of the Sun.
Do these ideas change with age? Consider using the "Objects in the Sky" probe or asking the question, "When do you see the Moon: daytime, nighttime, or both?" across multiple grades from first- through fifth-grade. Share your data and look for differences in students' ideas. Probe further to find out why students think the Moon is only visible during the evening. If students believe the Moon can be seen in the daytime, probe to find out what phases they think can be observed during the day. Consider other factors that may have influenced their thinking that the Moon is visible only in the nighttime. For example, children's storybooks, trade books, and instructional materials almost always show the phases of the Moon in a dark, nighttime sky. Instead of telling students that the Moon is visible in the daytime, take them outside during a phase when it is visible in the morning or afternoon sky and let them see it for themselves. Continue making daytime observations of the Moon, when visible, to reinforce that we can sometimes see the Moon during the daytime. Have students record the time and position of the Moon in the daytime sky and the phase present.
Figure 1. Objects in the Sky. Objects in the Sky Different things tan be seen in the sky. Put a D next to die things that ire seen only in the daylight. Put an N next to the things that can be seen only at night. Put a B next to the things that can be seen in both day and night. -- the Sun -- the Moon -- the next-nearest star to our Sun -- constellations Explain your thinking. How did you decide when you could see different things in the sky?
This probe points out that when students have seen something, they don't necessarily believe it. By con fronting students with their idea that the Moon is only visible at night through a direct experience of observing the Moon during the daytime, you may help your students give up their misconception. Furthermore, the probe is formative in nature by pointing out the importance of not limiting students' observations to a nighttime context. When the Moon is visible during the school day, encourage students to make their monthly observations then, as well as in the evening (which is necessary for them to see the full Moon because it rises when the Sun sets and sets as the Sun rises). By using this probe, perhaps you will see the old adage change to "believing is seeing!"
American Association for the Advancement of Science (AAAS). 2009. Benchmarks for science literacy. www.project2061.org/ publications/bsl/online
Keeley, P., F. Eberle, and J. Tugel. 2007. Uncovering student ideas in science: 25 more formative assessment probes. Arlington, VA: NSTA Press.
National Research Council (NRC). 2011. A framework for K-12 science education: Practices, cross-cutting concepts, and core ideas. Washington, DC. National Academies Press.
Plummer, J. 2009. Early elementary students' development of astronomy concepts in the planetarium. Journal of Research in Science Teaching 46 (2): 192-209.
Vosniadou, S., and W. Brewer. 1994. Mental models of the day/night cycle. Cognitive Science 18: 123-183.
Uncovering Student Ideas www.uncoveringstudentideas.org
Download the "Objects in the Sky" probe at www.nsta.org/SC1201.
Assessment serves many purposes in the elementary classroom. Formative assessment, often called assessment for learning, is characterized by its primary purpose--promoting learning. It takes place both formally and informally, is embedded in various stages of an instructional cycle, informs the teacher about appropriate next steps for instruction, and engages students in thinking about their own ideas. Formative assessment can take many forms. One form that has been used successfully in science education is the formative assessment probe. The Uncovering Student Ideas in Science series published by NSTA provides science educators with an extensive bank of formative assessment probes (see Internet Resource for information on the series). These probes are used to reveal the ideas students bring to their learning before instruction (preconceptions) as well as the conceptions formed throughout the instructional cycle. Merely gathering this information does not make a probe formative. It is only formative when the information is used to improve teaching and learning. Each month, this column features a probe and describes how elementary science teachers can use it to build their formative assessment repertoire and improve teaching and learning in the elementary science classroom. See NSTA Connection for more background on using formative assessment probes.
Page Keeley (email@example.com), author of the Uncovering Student Ideas in Science series, is the senior science program director at the Maine Mathematics and Science Alliance in Augusta, Maine, and former NSTA President.…