Magazine article Online

Online Spotlight: Squishy Boolean

Magazine article Online

Online Spotlight: Squishy Boolean

Article excerpt

Dialog was one reason that I was drawn, back in the 1970s, to the library profession. I graduated from college with a B.A. in mathematical philosophy, then stumbled into a job in a law firm library, where the librarians taught me the rudiments of Dialog searching. "Aha," I thought. "It's structured, it's logical, it's powerful, it has nested logic! I must get my M.L.S. to learn more about this!" This was the essence of Boolean.

For long-time online searchers, a major impact of search engines was the increased attention paid to non-Boolean search algorithms-the "preferably includes" in addition to "must include" and "must not include" options. The first time I saw this Third Way on the advanced search page of a search engine, I knew I'd seen the most revolutionary development since interactive searching hit the online world in the early 1970s. It was Boolean for us laid-back types: "Hey, let's not get all uptight about this AND and OR, OK?"

Interestingly, Dialog is the only one of the big three online services that offers any real version of squishy Boolean, and it's buried in a little-known command called TARGET. Using this command, you type in the words you want to search. The results may include records that contain a combination of some but not necessarily all of the terms. You can flag mandatory terms with an asterisk. (see support.dialog.com/searchaids/success for more information.) LexisNexis offers the ability to set the "relevance threshold" of its Smartlndexing (controlled vocabulary) terms, although not free-text search words. You can specify a Major Reference, Strong Passing Reference, or Weak Passing Reference. (see www.lexisnexis.com/infopro/smart indexing/ for more information.)

What has impressed me lately is the rise in squishy Boolean within the Web search engines. When MSN rolled out its search engine, I was struck by the Results Ranking option that, as of early 2005, is still in beta. Go to beta.search.msn.com and click the "Search Builder" link, then the "Results Ranking" link. Whoa-you can now use slider bars to tell MSN exactly how important it is to see recently updated or more "popular" (that is, linked-to) sites and whether you want exact matches to all your search terms, "approximate" matches, or matches that fall anywhere in between.

Google's Personalized Web Search (in beta as of early 2005) offers similar squishy logic. Go to labs.google.com/ personalized, tell Google what types of Web searches you commonly do (chemistry, photography, gardening-whatever! …

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