A process of abstraction initiates the development of a theory of applied linguistics, beginning with the distinction between technical norm and technical fact. Each applied linguistic intervention has a normative dimension and a factual interface with its users. The second step is to abstract the qualifying technical modality of these artefacts, holding it up for theoretical scrutiny. When this is done, we discover that the technical modality is unique, but coheres with the other aspects of experience. That inter-modal coherence is the basis for applied linguistic concept formation that includes both constitutive concepts and regulative ideas. [For the complete volume, "A Theory of Applied Linguistics: ?magining and Disclosing the Meaning of Design. Educational Linguistics. Volume 65," see ED672528.]