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.