The Colorado Learning Attitudes about Science Survey ͑CLASS͒ is a new instrument designed to measure student beliefs about physics and about learning physics. This instrument extends previous work by probing additional aspects of student beliefs and by using wording suitable for students in a wide variety of physics courses. The CLASS has been validated using interviews, reliability studies, and extensive statistical analyses of responses from over 5000 students. In addition, a new methodology for determining useful and statistically robust categories of student beliefs has been developed. This paper serves as the foundation for an extensive study of how student beliefs impact and are impacted by their educational experiences. For example, this survey measures the following: that most teaching practices cause substantial drops in student scores; that a student's likelihood of becoming a physics major correlates with their "Personal Interest" score; and that, for a majority of student populations, women's scores in some categories, including "Personal Interest" and "Real World Connections," are significantly different from men's scores.

Quantum mechanics is difficult to learn because it is counterintuitive, hard to visualize, mathematically challenging, and abstract. The Physics Education Technology (PhET) Project, known for its interactive computer simulations for teaching and learning physics, now includes 18 simulations on quantum mechanics designed to improve learning of this difficult subject. Our simulations include several key features to help students build mental models and intuitions about quantum mechanics: visual representations of abstract concepts and microscopic processes that cannot be directly observed, interactive environments that directly couple students' actions to animations, connections to everyday life, and efficient calculations so students can focus on the concepts rather than the math. Like all PhET simulations, these are developed using the results of education research and feedback from educators, and are tested in student interviews and classroom studies. This article provides an overview of the PhET quantum simulations and their development. We also describe research demonstrating their effectiveness and share some insights about student thinking that we have gained from our research on quantum simulations.

Metal films grown on nonwetting substrates evolve from an early stage of isolated compact islands to a later stage of elongated islands and percolation. Results are presented of a scanning electron microscopy study of Pb on SiO2 showing that the critical island radius Rc at which this crossover occurs is strongly dependent on temperature and weakly dependent on deposition rate. The experimental results are semiquantitatively described by a kinetic freezing model, in which the rate of island coalescence due to surface diffusion competes with the rate of island growth due to deposition.

The Physics Education Technology (PhET) project creates useful simulations for teaching and learning physics and makes them freely available from the PhET website (http://phet. colorado.edu). The simulations (sims) are animated, interactive, and game-like environments in which students learn through exploration. In these sims, we emphasize the connections between real-life phenomena and the underlying science, and seek to make the visual and conceptual models of expert physicists accessible to students. We use a research-based approach in our design-incorporating findings from prior research and our own testing to create sims that support student engagement with and understanding of physics concepts.We currently have about 50 sims posted on our website. Many of the sims cover introductory high school and college physics, while others introduce more advanced topics, e.g., lasers, semiconductors, greenhouse effect, radioactivity, nuclear weapons, and Fourier analysis. Users, however, have included students from grade school through graduate school. On the website, the sims are organized under nine loose

T he Physics Education Technology (PhET) project creates useful simulations for teaching and learning physics and makes them freely available from the PhET website (http://phet. colorado.edu). The simulations (sims) are animated, interactive, and game-like environments in which students learn through exploration. In these sims, we emphasize the connections between real-life phenomena and the underlying science, and seek to make the visual and conceptual models of expert physicists accessible to students. We use a research-based approach in our design-incorporating findings from prior research and our own testing to create sims that support student engagement with and understanding of physics concepts. We currently have about 50 sims posted on our website. Many of the sims cover introductory high school and college physics, while others introduce more advanced topics, e.g., lasers, semiconductors, greenhouse effect, radioactivity, nuclear weapons, and Fourier analysis. Users, however, have included students from grade school through graduate school. On the website, the sims are organized under nine loose