Sam Reid

PhET: Interactive Simulations for Teaching and Learning Physics

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.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.

Developing and researching PhET simulations for teaching quantum mechanics

Quantum mechanics is counterintuitive, difficult to visualize, mathematically challenging, and abstract. The Physics Education Technology (PhET) Project now includes 18 simulations on quantum mechanics designed to improve the learning of this subject. These simulations include several key features to help students build mental models and intuition 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 that students can focus on the concepts rather than the mathematics. Like all PhET simulations, these are developed using the results of 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 discuss some i...

Regularized Linear Models in Stacked Generalization

Stacked generalization is a flexible method for multiple classifier combination; however, it tends to overfit unless the combiner function is sufficiently smooth. Previous studies attempt to avoid overfitting by using a linear function at the combiner level. This paper demonstrates experimentally that even with a linear combination function, regularization is necessary to reduce overfitting and increase predictive accuracy. The standard linear least squares regression can be regularized with an L2 penalty (Ridge regression), an L1 penalty (lasso regression) or a combination of the two (elastic net regression). In multi-class classification, sparse linear models select and combine individual predicted probabilities instead of using complete probability distributions, allowing base classifiers to specialize in subproblems corresponding to different classes.

Parallel DOM Architecture for Accessible Interactive Simulations

Interactive simulations are used in classrooms around the world to support student learning. Creating accessible interactive simulations is a complex challenge that pushes the boundaries of current accessibility approaches and standards. In this work, we present a new approach to addressing accessibility needs within complex interactives. Within a custom scene graph that utilizes a model-view-controller architectural pattern, we utilize a parallel document object model (PDOM) to create interactive simulations (PhET Interactive Simulations) accessible to students through alternative input devices and descriptions accessed with screen reader software. In this paper, we describe our accessibility goals, challenges, and approach to creating robust accessible interactive simulations, and provide examples from an accessible simulation we have developed and possibilities for future extensions.