The developer of applications software for databases must translate requirements expressed in terms of the application domain into operations understood by database schemaoriented tools. This is a nontrivial mapping involving differing data representations, expression of conceptual operations in procedural logic and DML, and understanding of data semantics and the maintenance of data consistency all over and above the conventional difficulties of communicating requirements from users to programmers. This paper describes an application development toolkit which offers an alternative approach to the development of databaseintensive applications through the direct support of application area specialists and end users in the production of complete application sets to meet their own requirements. be reduced below zero, for example, but this may have to be explicitly prevented by an application. (This is a difference in conceptual models, not just a data consistency problem). ADT offers a means of combining various tools, including the DBMS, and presenting their capabilities through simplified interfaces within a semantic frame of reference closer to the application domain. In effect, ADT enables the bridging of the "conceptual gap." Frame of Reference User/Application Specialist 'Using the pati number and quanlity hom the shipping slip, reduce the stock level' Application Application Domain w f i c Operatbns