From the earliest days of their lives, children are exposed to all kinds of sound, from soft, comforting voices to the frightening rumble of thunder. Consequently, children develop their own naïve explanations largely based upon their experiences with phenomena encountered every day. When new information does not support existing conceptions,…

Contextualized items have been widely used in science testing. Despite common use of item contexts, how the influence of a chosen context on the reliability and validity of the score inferences remains unclear. We focused on sequential cues of contextual information, referring to the order of events or descriptions presented in item contexts. We…

Earth's surface is constantly changing. Weathering, erosion, and deposition break down Earth materials, transport those materials, and place them in new locations. Children see evidence of these processes all around them. The sidewalk or playground surface cracks and has plants growing in it. Pieces of a rock wall or the sides of a building…

The purpose of this paper is to carefully examine the evolution of students' theory building and modeling, critical components of scientific epistemologies, over a unit of study on sinking and floating in one third/fourth grade classroom. The study described in this paper follows in the tradition of Design Experiments (Brown 1992, Collins 1990)…

Explanation as a genre may support children's reasoning and understanding particularly effectively. In this study, 20 fourth graders were given the task of explaining the effects of a pollutant on an ecosystem to third graders. Before writing, they completed a commercially developed science unit, instruction in reading and writing an explanation,…