ISR11 Summary summary Harvard University Gerard Salton Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. The concordance program described in section III is presently being distributed through the SHAlE organization. In section Iv by M. Lesk and G. Salton the complete information dissemination process is examined with emphasis on the use and construction by automatic or semi-automatic techniques of syno[OCRerr] dictionaries and hierarchical subject arrangements. One specific proposal for the fully automatic construction of subject hierarchies is presented in section VIII by G. Bloggren, A. Goodman, and L. Kelly. It is shown in particular how the structure of the hierarchical arrangement changes as various parameters are changed. Section V of this report by M. Lesk and G. Salton contains in summary form the systems evaluation output produced by the SM[OCRerr]T system, based on extensive operations with four document collections in three subject fields (documentation, caii[OCRerr]uter science, and aerodynamics). One document collection used in the experiments consists of document abstracts manually indexed by trained indexers, thus permitting a comparison between the effectiveness of the standard [OCRerr]eyword rn[OCRerr]tching techniques and the automatic analysis procedures incorporated into the S[OCRerr]T system. Another collection was available in the form of abstracts as well as longer summaries, thus permitting an e[OCRerr]valuation of the effects of document length. Three sections are devoted to a study of iterative search techniques and user feedback techniques, including sections VI, VII, and Ix. Section VI by W. Riddle, T. Horwitz, and R. Dietz examines the effecti[OCRerr]ene.ss of a variety of relevance feedback procedures in which the users supply to the system relevance judgments about documents previously retrieved. These xv