Glossary » domain expert
or “subject matter expert” (SME); a person with special knowledge or skills in a particular area; a person extremely familiar with a given group of users and their work habits (because they belong to the group).
A truck driver is an expert in trucking and the needs truckers have for the types of systems that truckers might use, such as delivery or inventory systems. A manager may be a domain expert for project management systems. An accountant is a domain expert for accounting systems.
Programmers and user interface designers need to interview domain experts and work with domain experts in the design of systems for the expert’s field.