CASE HISTORIES ARE SUMMARIZED FOR 12 RESEARCHERS IN SCIENCE AND ENGINEERING AT THE FLORIDA STATE UNIVERSITY, I.E., 6 CHEMISTS, 4 BIOLOGISTS, 1 ENGINEER, AND 1 METEOROLOGIST. OVER A 10-MONTH PERIOD, 258 HISTORIES WERE OBTAINED. THE DATA DO NOT PERMIT THE DETERMINATION WITH CERTAINTY THE TYPE OF SUBJECT INDEX MOST SUITABLE FOR A PARTICULAR TYPE OF SUBJECT QUESTION. OVER 70 PER CENT OF THE INQUIRIES WERE SUBJECT QUESTIONS, AND OVER 80 PER CENT OF THESE REQUIRED ONLY A LOGICAL PRODUCT SEARCH. QUESTION-DOCUMENT TITLE PAIRS WERE ANALYZED FOR EACH OF 381 DOCUMENTS SELECTED AS ANSWERS TO 170 SUBJECT QUESTIONS. OF A POSSIBLE 1142 CONCEPTS, 604 QUESTION CONCEPTS WERE MATCHED BY DOCUMENT TITLE CONCEPTS. MATERIAL LESS THAN ONE YEAR OLD ACCOUNT FOR LESS THAN 1 PER CENT OF THE SELECTED DOCUMENTS. OVER 20 PER CENT OF THE SELECTED DOCUMENTS WERE OVER 10 YEARS OLD, AND INCLUDED A LOW INCIDENCE OF CONFERENCE PAPERS AND GOVERNMENT REPORTS. A KEY-WORD-OUT-OF-CONTEXT INDEX WILL BE TESTED IN FUTURE STUDIES. THIS DOCUMENT IS AVAILABLE AS AD-643-869 FROM THE CLEARINGHOUSE FOR FEDERAL SCIENTIFIC AND TECHNICAL INFORMATION, SPRINGFIELD, VIRGINIA 22151, $3.00 FOR HARD COPY, $0.65 FOR MICROFICHE, 16 P. A PAPER WITH THE SAME TITLE APPEARED IN THE PROCEEDINGS OF THE AMERICAN DOCUMENTATION INSTITUTE, OCTOBER 3-7, 1966, SANTA MONICA, CALIFORNIA, VOL. 3, 1966, P. 245-254. (AUTHOR)