Recently we have been assisting to an increase in the use of handheld software in education. Yet, in what concerns modeling and simulation, what we find most are closed packages, representing a specific situation, that once used become exhausted. We need tools that allow representing more situations easily and quickly. This motivated the development of Sim- H, an authoring system for handheld modeling and simulation that uses essentially di rect manipulation techni ques, various representation and interaction forms to create and test models and simulations. At the moment it is made by three editors, one for model building, or a modeling tool, a nother to create scenarios for models that are easier to interact with than the models themselv es, and a third one to include support to learning in a model or a scenario, namely extra information and guidance, that is to build simulations. Due to Sim-H architecture it is very easy to aggregate to a single model several scenarios or learning layers. In the scope of this paper we will focus mainly on the scenario editor, its characteristics and the kind of products it allows to build.