This report builds on theoretical foundations of tool-mediated learning, tool design, and human computer interaction to develop a framework for implicit scaffolding in learning environments. Implicit scaffolding employs affordances, constraints, cueing, and feedback in order to frame and scaffold student exploration without explicit guidance, and it is a particularly useful design framework for interactive simulations in science and mathematics. A key purpose of implicit scaffolding is to support a range of educational goals including affect, process, and content. In particular, the use of implicit scaffolding creates learning environments that are productive for content learning and are able to simultaneously support the affective goals of student agency and ownership over the learning process - goals that may not be addressed in more directed learning environments. We describe how the framework is applied in the context of the Energy Skate Park: Basics simulation, a simulation aimed at middle school student learning of energy concepts. Interview data provides an exemplar of the process by which implicit scaffolding can support productive student exploration with a computer simulation. While we present this framework for implicit scaffolding in the context of computer simulations, the framework can be extended and adapted to apply to a range of tool-mediated learning environments.