Formating

                    Text Prep


                       T

             NLP

                         Morph


                           I
                         Parsing


                           I
                      Candidate NPs


  Term/Doc
  Statistics         ~NP Scoring -

                     ~ Matching

   Thesaurus
                         Scoring -

          Filtering

                                     Lexicon
                                      `Core' Lex (100,000 items)
                                      Optional Su~Domain Lex


                                     `Heuristic' Grammar
                                      `Simplex' NP
                                      Optional "Complex" NP
                                      Optional "Full Sentence" Constituents


                                     General Set of Terms


                                     "Exact"


                                     "Novel"

                                     "General"

                                                Specific
                                                Set of Terms

   "1s~Order" Thesaurus: Flat List of Terms,
                     Implicit Compositional, Hierarchical Structure

                    Figure 1: `St~d&d' CLARIT Indexing Overview


         Formating


[~w

                    Text Prep

  NLP


Scoring

    I
   Morph


    I
   Parsing


    I
Candidate NPs

Lexicon
 `Core' Lex (100,000 items)


`Heuristic' Grammar
 `Simplex' NP

  Term/Doc_________       I
                   { NPs & Words{      General Set of Terms
  Statistics


                       Figure 2: Modified CLARIT Indexing in TREC


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