Boston University: Search Tips

Requiring or Excluding Terms

Infoseek has developed a simple query syntax which gives you the pinpoint search power of Boolean logic, without having to remember complex queries. The table below shows the Infoseek operators that correspond to Boolean operators:

Infoseek
operator Boolean
equivalent

default operator:
you need not use any
special symbols OR

+ AND

- NOT

phrase operator:
enclose the phrase with
double quotation marks ADJ

Boolean queries use the logical operators AND, OR, NOT and ADJ (adjacent). Suppose you wanted to find plain paper color laser printers made by companies other than HP. This query can be specified in Boolean logic as:

(laser ADJ printer) AND (color OR (plain ADJ paper)) AND NOT (HP OR Hewlett-Packard)

Using Infoseek operators, the complex query above may be typed into the search box as:

+"laser printer" color "plain paper" -HP, -Hewlett-Packard

This query specifies that:

All returned documents must contain the phrase "laser printer".
Documents containing one or more of the terms "laser printer", color, or "plain paper" will be ranked at the top (the more terms matched, the higher the ranking).
None of the documents returned will contain either HP or Hewlett-Packard.

Statistical Weighting and Infoseek Searches
A traditional Boolean search returns an unsorted list of all items that match the search condition. Infoseek goes considerably beyond this by using advanced statistical search technology to return the results sorted with the "best" matches listed at the top. Unlike plain Boolean searches, Infoseek automatically weights your query terms based on their statistical uniqueness. Common terms, such as "shall," get a much lower weighting than less frequently occurring terms, such as the phrase "golf courses."

Infoseek's advanced statistical weighting allows you to just type in relevant words and phrases, and the system will provide the answer to your query in the top few documents! Since there are cases in which it is convenient to narrow a query using Boolean operators, Infoseek allows you to use the + and - Boolean operators. With Infoseek, you get the accurate ranking of statistical searching combined with the information filtering of Boolean searching.

2 November 2000
Networked Information Services
Office of Information Technology
Boston University
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