SP500215 Appendix B: System Features Appendix National Institute of Standards and Technology D. K. Harman `B. CONSThUCIION OF INDICES, KNOWI£DGE BASES, AND OIlIER DATA STRUCIYURES -- STATISTICS ON DATA STRUCIVI es, when enoug[OCRerr][OCRerr] disk available --> needs > 100% scratch. )aragraph, sentence, word position). erm frequencies within document are stored. [OCRerr]n't know exact time, estimate 12 hours. Database was indexed by Stephen Walker at City University.