Authoring ITS domain models is a difficult task requiring many skills. Tools such as ASPIRE that model domains using ontology reduce the problem by allowing the author to work at a higher level of abstraction (and thus avoid low-level code writing), but such tools tend to be complex and the task is not intuitive for many people. To overcome this problem we have developed a framework for domain schema: highlevel abstractions that describe the semantics of the domain model for a class of domains. Using domain schema reduces the authoring effort to one of describing only those aspects that are unique to this particular domain; the schema provides the rest of the model. We describe the framework we have implemented and give some examples of domain types for which schema have been built.