The use of discrepant events in science instruction is a well-researched and well-documented teaching strategy. Simply put, a discrepant event is a surprising occurrence – one where the result is the opposite of what is expected. The counterintuitive and often paradoxical results prompt the question Why does that happen? in a real and meaningful way.
There are many examples of discrepant events available to science teachers. A teacher might open a lesson on gravity by dropping two objects of differing masses. Students will be surprised to see that the objects hit the ground simultaneously. In this article, we’re extending the idea of discrepant events to include video clips, in which students can observe the unusual path of the sun in the Arctic and Antarctica. The contrast with students’ own experiences qualifies these clips as discrepant events.
Research supports the use of discrepant events in the science classroom. First, discrepant events allow teachers to assess and target student preconceptions. When presented with a discrepant event, students are forced to reconsider their preconceptions and beliefs in light of the new evidence. Doing so creates cognitive conflict and can lead to conceptual change and learning.
Observing and investigating discrepant events is also motivating. Many discrepant events challenge “common sense” beliefs and can thus engage students who dislike traditional science class. Literacy is also easily integrated as students use the skill of observation to describe the event, form hypotheses, investigate the phenomenon, and discuss their findings with others.
In light of our focus on seasonal patterns in daylight at the poles, we’ve highlighted four video clips that can be used as discrepant events for students. Each clip is a time-lapsed video of the Sun’s path at a polar location. Watching the Sun’s movement in winter and summer is engaging and cognitively challenging for students and adults alike.
Note:The following videos are from YouTube. We recommend viewing the clips within this article. If it is necessary to view the video within the YouTube web site, please preview the site first to check for inappropriate content.
This video clip shows an early spring day in Igoolik, a small village in the Canadian Arctic.
Winter Sun Traverse (Fairbanks)
This video clip shows the path of the Sun just days after the winter solstice (December 21). Fairbanks, Alaska, is just south of the Arctic Circle.
Longest Day of the Year
This video clip shows the path of the Sun on the summer solstice (June 21) in Tuktoyaktuk, a village at the uppermost edge of Canada on the Arctic Ocean. Note that the sun does not set in the video! The clouds block the sun and make it seem darker than it really is!
Midnight sun time lapse (11:15pm to 02:45am)
This video clip shows the path of the Sun during the summer months in Alta, Norway.
Using This Discrepant Event in the Elementary Classroom
The four clips above will create cognitive conflict for many students. In their locations, the daily path of the Sun is much different from what is shown in the videos. The students’ previously held idea of the Sun rising and setting may seem completely at odds with the vivid images of the Sun “rolling” across the horizon or not setting at all. Upon watching the videos, many students will ask, “Why does the Sun do that?” or “How does that happen?”
The National Science Education Standards includes the cause of Earth’s seasons (variation in the Sun’s energy due to the Earth’s axis and length of day) in the Earth and Space Science content standard for grades 5-8. What then should be the focus for younger students?
The NSES Earth and Space Science content standard for grades K-4 recommends that students should know that “objects in the sky have patterns of movement.” The standards also state that “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” and that “emphasis in grades K-4 should be on developing observation and description skills and the explanations based on observations.” So even though a full understanding of the reason for the seasons is out of reach for most elementary students, it is important that they develop an understanding of seasonal patterns through observation and description.
Elementary students can observe the sun’s path firsthand and draw and record seasonal changes. The use of the video clips and other web-based resources and children’s literature can allow investigation into seasonal change and patterns of day and night in other locations, such as the polar regions.
Two online articles (see below) from the journal Science and Children, published by the National Science Teachers Association (NSTA), provide lessons and trade books to build on the curiosity inspired by the discrepant event. To access these free articles, you will first need to log in to the NSTA web site. Creating an online account with NSTA is free.
In “Seasons by the Sun,” students in K-3 read the book Sunshine Makes the Seasons and then trace and measure their shadows seasonally. Teachers can lead their students to reflect on and compare their observations. Students in grades 4-6 read Arctic Lights, Arctic Nights and record data from the story on a data sheet. Follow-up discussion and activities allow students to represent data graphically and begin to understand the connection between the seasons and day length. Students can then extend their understanding by collecting and graphing information for their hometown.
In “A Season to Inquire,” students in K-3 read Four Seasons Make a Year. They then draw a schoolyard scene repeatedly through the year, measuring shadow lengths, comparing observations, and making predictions and connections with each new observation. Students in grades 4-6 read Autumn (Winter & Spring) Across America, a three-book series by Seymour Simon. Students then investigate changes in temperature as a flashlight is held at different angles. The observed pattern, that direct light results in greater temperatures, can help students begin to explain the change in seasons and the difference between temperatures in their hometown and other locations.
Additionally, students can share data from their hometown with students across the country in collaborative projects. See Connecting Classrooms, Sharing Real Data from Issue Two for more information on these types of projects.
A Strategy Consideration
Some researchers have shown that the choice of teaching strategy when presenting a discrepant event influences the types of responses and conclusions drawn by students. Ideally, students have time for individual exploration of materials and resources and time to discuss findings, pose hypotheses, and generate questions in small groups. They should also receive guidance from the teacher both in small groups and as a class. While student motivation increases as a result of not simply being told the correct explanation, it is important that teachers provide support and guidance as groups of students strive to make sense of the event. Small-group discussion and exploration allow for the social construction of knowledge and engage students more fully than individual or whole-class work.
Inquiry-based activities will lead students to conclude that seasons are not the same across the world and that the polar regions have extreme seasons. Students who are firmly grounded in an understanding of seasonal patterns in their hometowns and an understanding that these patterns vary with geographic location will be ready to tackle the more abstract concepts underlying seasonal change in the middle school years.
Copyright May 2008 – The Ohio State University. This material is based upon work supported by the National Science Foundation under Grant No. 0733024. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work is licensed under an Attribution-ShareAlike 3.0 Unported Creative Commons license.