This paper presents a new definition of context for contextaware computing based on a model that relies on dynamic queries over structured objects. This new model enables developers to flexibly specify the relationship between context and context data for their context-aware applications. We discuss a framework, HyConSC, that implements this model and describe how it can be used to build new contextual hypermedia systems. Our framework aids the developer in the iterative development of contextual queries (via a dynamic query browser) and offers support for context matching, a key feature of contextual hypermedia. We have tested the framework with data and sensors taken from the HyCon contextual hypermedia system and are now migrating HyCon to this new framework.