Boolean operators for effective searches

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By Catherine Holland By Catherine Holland

Q. I'm working on a research project that requires me to use a variety of search engines to find things online. I can do basic searching by keyword, but I know there are better ways to search. I've read about something called Boolean searches, but in all honesty, I didn't understand what the heck I was reading. Can you help?

A. Launching Boolean (pronounced BOO-lee-an) searches, within search engines that support them, is an excellent way to increase your searching effectiveness. A Boolean search is a method that uses specific words, called operators, to narrow or focus search results.

The most frequently used Boolean operators are AND, OR, and NOT, though IF, THEN, NEAR and EXCEPT, are also Boolean operators. For example, launching a search for “movies AND advertising” (without the quotes), will yield search results that contain both words, “movies” and “advertising.” It’s best to capitalize Boolean operators because some search engines require that they be entered in all caps.


The operator NOT will exclude a word or words from the search results. For example, "pets NOT Chia."

For more information about Boolean searches, examples of searches using each operator, and a little history of its derivation, you are cordially invited to read my in-depth article at

Q. I keep getting a “404, Page Not Found” error. Is there anything I can do about that?

A. When the dreaded 404 error appears, many users conclude that a Web page no longer exists or that its address is incorrect. That’s not always the case.

The next time that error message rears its ugly header, click Refresh or Reload, depending on your browser. That will cause your browser to retrieve a fresh copy of the Web page, which will often solve the problem. This is also a good technique to use if you encounter a page that’s taking forever to load. Click Stop, then Refresh or Reload to try it again.

If that doesn't work, try returning a few hours later and try it again, in case it was just a transient problem with the Web site.

Last, but not least, be sure to periodically purge your browser’s cache. If you have an old copy of a Web page in your cache, that can create problems. If you're using IE 7, click Tools > Internet Options. On the General tab, under Browser History, click the DELete button. In IE 8, click Tools > Internet Options. On the General tab, under Browsing History, click the DELete button and delete Temporary Internet Files and Browsing History.

In all other browsers, go to your user settings and look for a button or buttons to clear Temporary Internet Files and History.

Mr. Modem's Sites of the Week:

Picture History
An online archive of images depicting more than 200 years of American history. Search by category, decade, or photographer.

The Black Sea: Can You Dig It?
If you ever wanted to make like Jacques Cousteau, but all that spooky, slimy underwater stuff gives you the heebie-jeebies, you can join a team of divers exploring the depths of the Black Sea, without getting your hair wet. Visit this interactive archaeology exploration of the wreck of the Pisa, a ship sunk in a 1277 battle. (Gosh, it seems like only yesterday.) Here you can track the expedition by viewing pictures, journal entries, and historical information.

For plain-English answers to your questions by email, plus helpful PC tips, subscribe to Mr. Modem’s Weekly Newsletter. For information, visit