Abstract
Biomedical information systems demand cooperative interfaces that maximize the flow of information between machine and user. Within the framework of the PENGUIN project—an object-oriented architecture for expert database systems—, we describe the use of hypertext tools for designing sophisticated interfaces to the relational-database component of PENGUIN. The interface designer employs HyperCard to construct a visual representation of the underlying database that requires the user to recognize rather than to recall the appropriate command name. We show that the resulting direct-manipulation style of interaction facilitates greatly information retrieval and presentation.