Searching with Boolean Operators

Are you having problems finding exactly what you want with just a keyword search? Advanced Search operators provide ways to further refine your search query. One type is the Boolean operator, named after British mathematician George Boole (1815-1864), who made a study of combining logic with mathematics. Major search services support Boolean operators, but each search service may implement them differently.

• Boolean operators Boolean operators are connecting words--words that you can use to specify relationships between the keywords or phrases in your search query. Boolean operators can be used as words or as symbols:

This operator requests that multiple words and phrases all be present in your query results and displays these results at the top of the list of results. However, most search engines and directories interpret this operator in a way that does not prohibit results that do not include all the words or phrases. Searching for education AND computer will return documents that contain both the word "computer" and the word "education" in them as the top results.

• Characteristics of Search Understanding how a search engine works helps you to understand how your pages are ranked in the search engine, but how your pages are found is another story entirely. That is where the human element comes in. Search means different things to different people. For example, one of my colleagues searches the Internet using the same words and phrases he would use to tell someone about a topic or even the exact question that he’s trying to get answered. It’s called natural language. Another, however, was trained in search using Boolean search techniques. She uses a very different syntax when she is creating a search term. Each of them returns different search results, even when each is using the same search engines. The characteristics of search refer to how users search the Internet. This can be everything from the heuristics they use when creating a search term to the selection the user makes once the search results are returned. One interesting fact is that more than half of American adults search the Internet every time they go online. And in fact, more people search the Internet than use the yellow pages when they’re looking for phone numbers or the locations of local businesses. This wealth of search engine users is fertile ground for SEO targeting. And the better you understand how and why users use search engines, and exactly how search engines work, the easier it will be to achieve the SEO you’re pursuing.
• What is Boolean Search? Boolean searches allow you to combine words and phrases using the words
  1. AND,
  2. OR,
  3. NOT and
  4. NEAR
  (otherwise known as Boolean operators) to limit, widen, or define your search. Most Internet search engines and Web directories default to these Boolean search parameters anyway, but a good Web searcher should know how to use basic Boolean operators.

When you select "all of the words" on a search page, it is the equivalent of keyword1 AND keyword2 AND keyword3... and so on. When you select "any of the words" on a search page, it is the equivalent of keyword1 OR keyword2 OR keyword3... and so on.
Although you can use symbols instead of the actual word, use of the actual word is recommended; different search engines may use different symbols to represent Boolean operators, but the actual words will always be the same.

You can compose search queries by grouping keywords and Boolean operators. This allows you to look for references that contain this AND that, but NOT something else.
The next lesson will introduce ways of refining a search that are more restrictive than AND, OR, and NOT, but Boolean operators may still be a good choice for some complex search queries.

Click the Exercise link below to compare search results with different Boolean operators and grouping.
Search Boolean Operators - Exercise