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Best Teaching Practices

Discrepant Events

Research Findings

There is little direct research evidence that using discrepant events promotes conceptual understanding. However, two of the practices included in this chapter (Learning Cycle Approach and Real-Life Situations) are thought to be effective because they frequently include discrepant events. Discrepant events are one form of anomalous data that help students focus on their prior conceptions, a step that is thought to be necessary if students are to alter their conceptions so that they become closer to the accepted scientific view. During the exploration phase of the learning cycle, students may confront anomalous data, or such data may be included in instruction based on real-world situations.

In the Classroom

Many science teachers use discrepant events frequently in their teaching, and this practice has been advocated by authors of methods texts over the years. An example of a discrepant event from physics instruction would be to drop a Styrofoam and a steel ball of equal volumes from the same height at the same time and note that both hit the floor at the same time. Because most students think that the heavier ball will hit first, the event is discrepant.

Although discrepant events frequently take the form of demonstrations, all demonstrations do not necessarily include discrepant events. Discrepant events can be built into hands-on activities that students actually perform and can be included in computer simulations and on video-products.

Just because students view or experience something that is discrepant does not guarantee that they will learn from the situation. Students may ignore or reject it. In order to maximize its effectiveness, the anomalous data must be credible and unambiguous. A recommended strategy for effective instruction includes the following steps: 1) consider a physical scenario of unknown outcome; 2) predict the outcome; 3) construct one or more theoretical explanations; 4) observe the outcome; 5) modify the theoretical explanation; 6) evaluate competing explanations; and 7) repeat the previous steps with another discrepant event illustrating the same theory or concept.

Steps one through five may be carried out in various ways. Research on the effective use of discrepant events suggests that teachers should neither confirm nor deny students' tentative explanations of the event but provide guidance and cues so that they can make explanations on their own. The social interaction from small-group and whole-group discussions, and from letting children interact with the materials, appears to facilitate conceptual understanding


Journal Articles - To access most of these Journal Articles, you must be a student, faculty or staff member at an OhioLINK affiliated institution. Access to OhioLINK may be available to Ohioans through their local, public, or school libraries. Contact OPLIN, INFOhio, or your local library for more information.

Step-Wise Evolution of Mental Models of Electric Circuits: A "Learning-Aloud" Case Study
The Journal of the Learning Sciences, Vol. 11, Issue: 4, October 1, 2002. pp. 389-452
Clement, John J.; Steinberg, Melvin S.

Various methods have been tried for fostering conceptual change in science including the use of analogies, discrepant events, and visual models. In this article we describe an approach to teaching complex models in science that takes a model construction cycle of generation, evaluation, and modification as an organizing framework for thinking about when to use each of the previous strategies. This approach of model evolution uses all of the previous methods as students are led...

Using Computers to Support a Beginning Teacher's Professional Development
Journal of Science Education and Technology, Vol. 9, Issue: 4, December 2000. pp. 367-373 3
Lin, Huann-shyang; Chiu, Houn-Lin

This study explored the efficacy of promoting a beginning chemistry teacher's curriculum development and teaching practices through the use of computers. Using pictorial analogies, historical cases of science, and discrepant events in a web site designed by the researchers as curricular samples, the beginning teacher was asked to develop similar curriculum for his own teaching. After taking the researchers' advice into account and making adjustments, the beginning teacher implemented the...

Lasting Effects of Instruction Guided by the Conflict Map: Experimental Study of Learning about the Causes of the Seasons
Journal of Research in Science Teaching, Vol. 42, Issue: 10, December 2005. pp. 1089 - 1111
Tsai, Chin-Chung; Chang, Chun-Yen

This study was based on the framework of the "conflict map" to facilitate student conceptual learning about causes of the seasons. Instruction guided by the conflict map emphasizes not only the use of discrepant events, but also the resolution of conflict between students' alternative conceptions and scientific conceptions, using critical events or explanations and relevant perceptions and conceptions that explicate the scientific conceptions. Two ninth grade science classes in Taiwan...

The Intriguing Physics Inside an Igloo
Physics Education, Vol. 36, Issue: 4, July 01, 2001. pp. 290-292
Gonzalez-Espada, Wilson J; Bryan, Lynn A; Kang, Nam-Hwa

The counter-intuitive fact that ice is a good insulator created a 'teachable moment' for describing the use of discrepant events as a strategy for science instruction and exploring a possible solution to the question, 'How warm can the...


This is a listing of references using toys and discrepant events.

The author of this article describes examples of her use of discrepant events in her teaching, gives a couple of examples of discrepant events, and encourages readers to add their experiences with this technique to the conversation.