Search engines work by providing you with a screen form containing one or more fields into which you type your search term (a combination of words and/or phrases). Single words are quick and easy, but produce much too general a result. With Google, for example, looking for florists yields 24 million hits (search results). If we narrow the search to florists in Vancouver (i.e. type florists Vancouver), we come up with 1.7 million results. Narrow further by making your search term a phrase. To do this, enclose the words in double quotation marks, as in "Vancouver florists". In Google, this example produces just 27,000 hits, because Google is making a match for the exact string of characters we typed.
Some search engines provide radio buttons that allow you to specify whether the search must match Any or All of the terms you type. Most default to All, returning pages that contain every word used in your search. Choose Any to retrieve pages that contain one or more of your search words. This AND versus OR distinction is called Boolean logic, and it's the key to controlling the search engines. To specify an OR in Google, you must type the word OR between words. In our Vancouver florists scenario, for example, typing florists OR vancouver results in 85 million hits because it returns all pages containing either the word florists or the word Vancouver. Thus, you might get florists in Hungary and welders in Vancouver! By combining ANDs, ORs, and phrases, you can begin to build truly powerful queries. Learn these techniques and many more powerful search strategies in our popular
Internet research course.
How the Search Engines Differ
The Web puts a variety of powerful search engines at your disposal, including Altavista, Google, All The Web, Teoma, Wisenut, and many more. Which is best? These tools vary in ease of use not to mention features. Your choice of search engine should be driven by the research challenge you face. Some search engines are better than others for particular purposes. See our
comparison chart for an at-a-glance syntax summary, and see below for brief descriptions of today's major players, their respective strengths and weaknesses, and their affiliations:
Google: Google is the world's most popular search engine. Claiming to search 3.3 billion pages (that's practically the entire Web!), this search engine remains undisputed king in terms of size. Google produces highly relevant results, using link popularity for ranking. Google's original claim to fame was its speed, although its clean, uncluttered interface has also won fans. Google defaults to AND when processing queries containing two or more words (returning pages that match all words specified). If you want either word (as in alternate spellings of color), you must actually force Google to see your search this way, by specifying the Boolean OR operator, as in
color OR colour. Google supports exact phrase searching plus the ability to exclude words (use the minus sign) and to constrain by domain and other criteria.
Alliances: Google has taken over the Deja newsgroup archive. It powers hundreds of other search engines and the web search feature of directories like Yahoo. Google's Web directory is provided by DMOZ.
Altavista: Still the champ in terms of raw search power, Altavista was recently purchased by Overture, the Net's major pay-per-click search company. Altavista's index is respectable, at 1 billion pages. It defaults to OR, ordering search results according to number, location and proximity of search term occurrences. Use Altavista when you need to construct complex queries containing nested combinations of AND and OR. Altavista supports the quasi-Boolean operators (+, -) and the formal Boolean operators (AND, OR, AND NOT, NEAR). This search engine allows you to constrain your search by domain, location within page, date, and numerous other criteria. Drawbacks include notoriously buggy hit counts and an interface that could stand some usability improvements.
Alliances: Altavista, too, powers hundreds of other sites. Its web directory is provided by DMOZ.
All The Web: At first glance, All The Web looks much like Google, providing the clean look and user-friendliness of the industry leader. All The Web defaults to AND, with a convenient tick box that allows you to specify a phrase. Its index rivals Google's, at 3.2 billion documents. It does not recognize formal Boolean arguments, although it supports quasi-Boolean operators (+, -) and the ability to constrain by domain, location within page, and several other criteria.
Alliances: All The Web was also recently taken over by Overture.
Wisenut: Known for its clean screen and speedy performance, Wisenut set out to rival Google. A "clustering" search engine, Wisenut groups results into categories it calls "WiseGuide." Small plus and minus signs allow you to collapse and expand these categories. Like Google, Altavista, and other major players, Wisenut is a spider-based search engine that crawls links and indexes page contents. Wisenut claims to have an index of 1.5 billion pages. Wisenut defaults to AND, and supports phrase searching and the + and - operators, though it offers no advanced search features as yet.
Alliances: Wisenut is owned by Looksmart.
Teoma: Like Wisenut, Teoma set out to emulate Google's clean screen and fast performance. It too defaults to AND. Teoma's index is a respectable 1.5 billion pages. Like Google, Teoma evaluates page popularity, using complex relevance and link popularity algorithms to rank results. Teoma clusters search results at the top of the screen and displays a list of what it calls "Expert Link Collections" at bottom right. These listings point to sites Teoma considers authoritative link collections relevant to the subject of your search. Sometimes called
jumplists, link collections can be among the Web's hidden treasures. Teoma is one of the few search engines to identify them. This feature alone makes it a valuable addition to your bookmark list.
Alliances: Teoma was acquired by Ask Jeeves in 2001.
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