In this paper the existing functions of, and a number of future requirements for, information retrieval systems are dis cussed. Two basic requirements for free text information retri eval systems have been identified; one for a more general information modelling language and the other for a simple user interface for complex ad-hoc queries. The paper describes some existing and proposed hardware and software methods for implementing free text information retrieval systems. Emphasis is placed on methods of improving the functionality of the system rather than on methods of increasing the performance. It is suggested that considerable improvements can be achieved by a more imaginative use of existing hardware, though it is realised that special purpose architectures will play an increas ingly important role in information systems. The paper con cludes with a design for a new information retrieval system based on the use of the Binary Relationship Model for infor mation storage and retrieval, and an interactive graphical dis play for the user interface.
New measures for the evaluation of interactive information retrieval systems: Normalized task completion time and normalized user effectiveness
