A number of design models have been proposed in the area of Human-Computer Interaction (HCI) to support user-centered system design. el, abstract task models and detailed interface specification languages are among the most widely used. However, the need for designing applications to run in a number of different devices and platforms presents new issues that must be addressed from a platform-separable perspective. In this paper, we show how an interaction-as-conversation metaphor may face this challenge, and present an interaction modeling language that allows designers to build a blueprint of the range of interactions that will be able to take place in the application. Our goal is twofold: to motivate the designers to reflect upon the interactive solution they are creating, and at the same time provide a skeleton interaction specification that may be easily instantiated for different platforms or devices.