We propose a framework for an Intelligent Tutoring System to support instructors in the design of a training. This requires the partial capture of Instructional Design theories, which define processes for the creation of a training and outline methods of instruction. Our architecture is based on a knowledge representation that is based on the use of ontologies. Reasoning based on Description Logics supports the modelling of knowledge, the retrieval of suitable teaching methods, and the validation of a training. A small exemplary ontology is used to demonstrate the kind of Instructional Design knowledge that can be captured in our approach.