SP500215 Appendix B: System Features Appendix National Institute of Standards and Technology D. K. Harman IA. CONSTRUCTION OF INDICES, KNOWLEDGE BASES, AND OilIER DATA STRUCTURES -- MEIHODS USED SYSThM NAME [OCRerr]__ADS UIC [2] MEAl) [OCRerr] UIF J IDSR [OCRerr] Stopword Ust Yes [OCRerr] Yes [OCRerr] No [OCRerr] Yes Yes -\ - Number of Words 421 632 None 166 (6] 399 Controlled Vocabulary No No No No No Yes, but Stemming Yes (adsl) Yes No not used Yes Extracted from SMART, coded in lovins, - Standard Algorithms Paice, 1990 SPlIBOL None modified Paice - Morphological Analysis No No No None No Term weighting No IDF [3] No tf * idf Yes Yes Phrase Discovery No Yes No No No - Kind of phrase _____________ [4] None __________ _________ ____________ Statistics on word pairs computed & - Statistical Methods used None - Syntactic Methods No None __________ ____________ Syntactic parsing No No None No No Word Sense Disambiguation No No No Yes [7] No ___________ Heuristic Associations No No No No - Short Definition word co[OCRerr]occurrences None Spell Checking (With Manual Correction) No No No No No Spelling Correction No No No No No Proper Noun Identification No No No No No Tokenizer No No No No No - Which Patterns Use of Manually Indexed Terms No No No No No Other Techniques to Build Data List of Structures Yes (1] offsets [5] None