The information seeking and use habits of more than 600 scientists and engineers on staff at the European Space Agency (ESA) were studied and compared with those of staff at five European organizations with similar missions: the United Nations Education, Scientific, and Cultural Organization (UNESCO) in France; the International Atomic Energy Agency in Austria; Deutsche Forschungs und Versuchsanstalt fuer Luft und Raumfahrt (DFVLR) in West Germany; Nationaal Lucht en Raumtevaartlaboratorium (NLR) in the Netherlands; and the Centre National d'Etudes Spatiales (CNES) in France. Following an overview of the basic characteristics and traits of scientists and engineers, the report reviews the project's major findings as they relate to the type of information required by scientists and engineers: (1) its availability; (2) oral and written sources from which the information is obtained; (3) scientists' and engineers' awareness of the sources; (4) how they keep up-to-date; (5) time spent seeking the information; (6) the use made of the library or information center; and (6) patterns of communication. Twelve general suggestions are made for improving the communication and information flow within organizations to enhance the satisfaction of the information users. (SD)