An advanced data management system developed by the project on Computer Aids to Human Intellect sponsored by the Information Systems Program of ONR has been placed into regular service on the RCA SPECTRA 70/46G time-shared computer system at the Moore School of Electrical Engineering of the University of Pennsylvania. This system provides extensive facilities for information storage and retrieval, multi-level access control, and general problem solving. Incorporating a number of new concepts in the areas of file structure, data protection, and time-shared operating systems for large-scale computers, the new data management system represents a major portion of the work carried out over the past several years. The system allows file owners to specify various types of access not only to their files, but to records of information within those files as well. The generalized file structure incorporated in the system, and its associated storage and retrieval algorithms, permit the user to choose among a number of possible file structures, including the well-known inverted, multilist and index-sequential files. Such a choice of file structures in a single system has never before been available. The system also provides for the definition of problem solving procedures and allows user's programs to request data management service during execution.