TWO CHEMISTRY GRADUATE STUDENTS WERE TRAINED IN INDEXING TECHNICAL DOCUMENTS THROUGH AN ESTABLISHED TRAINING PROGRAM WHICH WAS MODIFIED FOR IMPROVEMENT. A STUDY OF INTRA- AND INTERINDEXER CONSISTENCY WAS MADE BY SUBJECTING A GROUP OF TECHNICAL DOCUMENTS TO INDEPENDENT INDEXING BY VARIOUS INDIVIDUALS AND TWO OF THE SAME INDIVIDUALS ONE YEAR LATER. THE CONCEPT OF ESSENTIAL INDEX TERMS WAS INTRODUCED. STATISTICAL ANALYSIS SHOWED THAT INTRA- AND INTERINDEXER CORRELATION FOR EXPERIENCED INDEXERS OF ESSENTIAL TERMS IS SIGNIFICANT WITH A PROBABILITY (P)0.999. THIS CONSISTENCY INDICATES THAT AN EXPERIENCED INDEXER'S INDEXING CAN SERVE AS A REFERENCE STANDARD FOR EVALUATING TRAINEES' WORK. IN EVALUATING TRAINEES, ESSENTIAL TERMS WAS A BETTER PERFORMANCE CRITERION THAN TOTAL TERMS AND HIGH INTERINDEXER CONSISTENCY WAS ACHIEVED. IN THE OPERATIONS OF THE DOCUMENT RETRIEVAL SYSTEM, SEARCH REQUESTS DECLINED FROM THE PRECEDING YEAR, AND POSSIBLE REASONS FOR THIS ARE ANALYZED. A SELECTIVE DISSEMINATION OF INFORMATION (SDI) PROGRAM WITH "CHEMICAL ABSTRACTS" WAS INITIATED, AND IN ORDER TO INCLUDE INFORMATION SCIENCE DOCUMENTS IN THE AEROSPACE MATERIALS INFORMATION CENTER (AMIC) DOCUMENT RETRIEVAL SYSTEM, A VOCABULARY AND THESUARUS FOR INFORMATION SCIENCE TERMS ARE BEING DEVELOPED. APPENDED ARE THE CALCULATIONS FOR INTERINDEXER CONSISTENCY, TYPICAL INDEX CARDS USED FOR THE STUDY, SEARCH REQUESTS PROCESSED, AND A DESCRIPTION OF THE CAS SDI PROGRAM AND TYPICAL USER PROFILES. THIS DOCUMENT IS AVAILABLE AS AD-666-462 FROM THE CLEARINGHOUSE FOR FEDERAL SCIENTIFIC AND TECHNICAL INFORMATION, SPRINGFIELD, VIRGINIA 22151, $3.00 FOR HARD COPY AND $0.65 FOR MICROFICHE, 76 PAGES. A RELATED DOCUMENT IS ED 015 002, A DESCRIPTION OF THE TRAINING PROGRAM AND IMPROVEMENTS IN THE AMIC SYSTEM. (AUTHOR/JB)