This column provides ideas and techniques to enhance your science teaching. This month's issue discusses how children think about the small-particle model of matter. What Richard Feynman referred to as the "atomic hypothesis" is perhaps more familiar to us as the small-particle model of matter. In its most basic form, the model states…

The purpose of this study was to investigate in detail the processes involved when the promotion of metaconceptual evaluation facilitates fifth grade students' construction, evaluation, and revision of their explanations for magnetic phenomena. Although much recent research emphasized the importance of student modeling and model construction,…

This study addressed the problem of why students with learning disabilities in mathematics too often fail to develop multiplicative and divisional concepts/operations. We conducted a constructivist teaching experiment with 12 students (nine 5th and three 4th graders). This report focuses on three students' conceptual progress, particularly on…

The time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004) assumes that during complex working memory span tasks, attention is frequently and surreptitiously switched from processing to reactivate decaying memory traces before their complete loss. Three experiments involving children from 5 to 14 years of age…

This standard lesson on identifying salt and sugar crystals expands into an opportunity for students to develop their observation, questioning, and modeling skills. Although sugar and salt may look similar, students discovered that they looked very different under a magnifying glass and behaved differently when dissolved in water. In addition,…