AREAS INVESTIGATED INCLUDE SLOW MEMORY DATA STORAGE, THE PROBLEM OF DECODING FROM AN INDEX TO A SLOW MEMORY ADDRESS, THE STRUCTURE OF DATA LISTS AND DATA LIST OPERATORS, COMMUNICATIONS BETWEEN THE HUMAN USER AND THE SYSTEM, PROCESSING OF RETRIEVAL REQUESTS, AND THE USER'S CONTROL OVER THE RETURN OF INFORMATION RETRIEVED. LINEAR, LINKED AND INVERTED FILE STRUCTURES ARE CONSIDERED. EMPIRICAL DATA FROM THE REPOSITORY OF THE ASSOCIATION FOR COMPUTING MACHINERY ARE USED FOR ILLUSTRATIVE PURPOSES. THESE DATA ARE ALSO USED IN THE PORTION OF THE DECODING MECHANISM STUDY WHICH DEALS WITH THE EFFECTS OF TRUNCATION OF INDEX TERMS. FOLLOWING THE FILE ORGANIZATION STUDY, THE NECESSARY LIST STRUCTURES AND LIST OPERATORS ARE DESIGNED. AN EDITING LANGUAGE FOR USE BY THE HUMAN OPERATOR IN COMMUNICATING WITH THE SYSTEM IS SPECIFIED, AS ARE REQUIREMENTS FOR THE EXECUTION OF "BACKGROUND" PROGRAMS WHEN A USER'S INFORMATION RETRIEVAL REQUEST IS NOT BEING PROCESSED. FINALLY, A SIMPLE SEQUENCE OF MAN-MACHINE COMMUNICATIONS WHICH ALLOWS THE USER OF THE SYSTEM TO SPECIFY WHAT CLASSES OF DATA ARE TO BE RETURNED TO HIM IS OUTLINED. THIS DOCUMENT IS AVAILABLE AS AD-647-196 FROM THE CLEARINGHOUSE FOR SCIENTIFIC AND TECHNICAL INFORMATION, SPRINGFIELD, VIRGINIA 22151, $3.00 FOR HARD COPY, $0.65 FOR MICROFICHE, 136 PAGES. (AUTHOR)