The objectives of this study were: (1) to create a set of computer programs capable of practical associative processing of NASA's growing document collection, (2) to process the collection with these programs, exhibiting the achievement of a capability to perform associative search of the collection, and (3) to study the use of statistical associations in large collection, by assessing the experiences gained during limited test operation of the system. The report is organized in three parts. The summary (Part I) itemizes principal resources that have been created and states conclusions. Part II illustrates the operation of the associative retrieval system and related topics, and Part III contains the detailed description of the complete system. (RP)