From gilbertd Wed Feb 10 20:20:33 1993
Received: by chipmunk.bio.indiana.edu
	(4.1/9.7jsm) id AA11614; Wed, 10 Feb 93 20:20:32 EST
Date: Wed, 10 Feb 93 20:20:32 EST
Subject: Booleans, partial and literal searches
From: "Don Gilbert" <gilbertd>
To: don
Status: R

			                                
			                                1 Nov 92

  The default WAIS and Gopher search provides an implicit "or"
  between words, so that all items matching any of the words in
  a query are returned, but those items with the most matches are
  at the top of the list.  Only full words are matched.  Case
  of letters is ignored.  By default, all symbols are ignored
  and treated as word breaks.  Only letters and digits are
  considered word parts.

  New features for searches thru IUBio Gopher and WAIS include
  boolean operators "and" and "not", partial word matches,
  literal phrase matches, and extended number of results.
 

 Boolean searches: The terms "and" and "not" are effective 
    in modifying the query.   For example,
    
    Query: red and green not blue
    Result: just those records with both the words "red" and "green",
            excluding all records with the word "blue".
            
 Partial words:  The asterisk (*) applied at the end of
    a partial word will match all documents with words that 
    start with the partial word.  For example,
    
    Query: hum*
    Result: all records with "hum", "hummingbird", "human",
            "humbug", etc.
            
 Literal phrases:  If quotes (') or double quotes (") surrounding
     a phrase, it will match that phrase exactly.  For example,
     
     Query: "red rooster-39"
     Result:  only those records with the the full string
            'red rooster-39' will be matched.

     There are some practical limits on this.  The first part
     of a literal must be a word that is otherwise indexed.
     Thus your literal cannot start with a symbol or other
     word delimiter.  Within quotes, the boolean operators
     and the partial word key are not active.
     
     
 These features can generally be mixed in a query, for example:
     Query:  "Df(32)-[34]red" and hum* not Brown        


 Results limit (Gopher only):  The maximum number of results that 
     are returned for a query is by default up to 200 (may change). 
     But you may set a higher, or lower, maximum by appending
     the greater than (>) symbol immediately followed by the
     number you wish at the end of your query.  For example,
     
     Query:  brown and cow* or "red rooster" >300
     Result:  up to 300 matches will be returned.
     
     
----
At this writing, all the search questions on this Gopher server
with the exception of the Genbank search now include these
features.  These search questions will soon be made available
thru WAIS as well as here in Gopher.


 


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