SP500207 NIST Special Publication 500-207: The First Text REtrieval Conference (TREC-1) Appendix C: System Features appendix National Institute of Standards and Technology Donna K. Harman .%`pecirlcati(Il and xtrdcti(n, f(r xample: a part or .%`peech tagger, a t(kernzer, a proper name recEpgnizer. We aI.%() did n[OCRerr][OCRerr]t explore the u.[OCRerr] (jf concept-l)ased techni(1ues (e.g., RUBRICFFOPNC) t(P provide low-level concepts as features. 486