In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

Typically, teachers use tests to evaluate students' knowledge acquisition. In a novel experimental study, we examined whether low-stakes testing ("quizzing") can be used to foster students' learning of course content in 8th grade science classes. Students received multiple-choice quizzes (with feedback); in the quizzes, some target…

Over a year, a small group of high school students risked their afternoons and summer to participate in a science program that was "much different from science class." This was one of several after-school programs in Oakland and Richmond that the author was leading as an instructor with the East Bay Academy for Young Scientists (EBAYS). Students…

How do people select among different strategies to accomplish a given task? Across disciplines, the strategy selection problem represents a major challenge. We propose a quantitative model that predicts how selection emerges through the interplay among strategies, cognitive capacities, and the environment. This interplay carves out for each…

Remote experimentation laboratories (REL) are systems based on real equipment that allow students to carry out a laboratory practice through the Internet on the computer. In engineering, there have been numerous initiatives to implement REL over recent years, given the fundamental role of laboratory activities. However, in the past efforts have…

This study examines first graders' epistemic reasoning, in tacit "practical epistemologies" reflected in thinking about an investigation of their own design. I analyzed children's epistemic reasoning, following a design experiment scaffolding increasing regulation of scientific inquiry in a domain they studied in depth. Participants…

The instructional design and the corresponding research on student learning of two virtual laboratories that provide an engineering task situated in an industrial context are described. In this problem-based learning environment, data are generated dynamically based on each student team's distinct choices of reactor parameters and measurements.…

Based on a three-year-long ethnography of the hobby of model rocketry, I present a practice-centered theory of interest relationships--that is, the pattern of long-term, self-motivated engagement in open-ended practices that has been theorized under the concept of "individual interests". In contrast to extant theories of individual interests, in…

This experiment examines the causal effect an electronic classroom response system (ECRS) has on students. Previous studies using an ECRS in the classroom indicate improved performance; however, many have confounds typical of classroom studies. To complement these studies, we conducted a laboratory study to minimize these confounds and concentrate…

This paper describes an enjoyable, simple, and inexpensive way to perform Young's two-source experiment using sound waves. The wave source is a simple aluminum rod (a "singing rod").

The similar mathematical forms of Coulomb's law and Newton's law of gravitation suggest that two uniformly charged spheres should be able to orbit each other just as two uniform spheres of mass are known to do. In this paper we describe an experiment that we performed to demonstrate such an orbit. This is the first published account of a…

People discriminate remarkably well among large numerosities. These discriminations, however, need not entail numerical representation of the quantities being compared. This research evaluated the role of both non-numerical and numerical information in adult judgments of relative numerosity for large-numerosity spatial arrays. Results of…

Terms to be familiar with before you start to solve the test: cytokines, cytokine receptors, cDNA library, cDNA synthesis, poly(A)[superscript +] RNA, primer, template, reverse transcriptase, restriction endonucleases, cohesive ends, expression vector, promoter, Shine-Dalgarno sequence, poly(A) signal, DNA helicase, DNA ligase, topoisomerases,…

Two students, meeting together with a teacher, redid historical experiments. Unlike conventional instruction where science topics and practices often fragment, they experienced interrelatedness among phenomena, participants' actions, and history. This study narrates actions that fostered an interrelated view. One action involved opening up…

In this article, the authors explored the existence of across-notation automatic numerical processing using size comparison and same-different paradigms. Participants were Arabic speakers, who used 2 sets of numerical symbols--Arabic and Indian. They were presented with number pairs in the same notation (Arabic or Indian) or in different ones…