Using Search Operators

In processing your search request, search engines and directories utilize rules to sort information known as search conventions. You can narrow your search and improve your chances of getting a meaningful results list by understanding search conventions and by using search operators. Search operators (sometimes referred to as qualifiers) are the symbols representing a specific action to be performed by the search engine or directory. The operators and conventions for searching are slightly different with each Web search tool, so using Help, Search Tips, and any local page hints and guides are recommended. Some of the operators and conventions are described that can boost the effectiveness of your search efforts.

Boolean Operators

Boolean operators were named after George Boole, a mathematician. They are logical terms used to combine keywords, such as AND, NOT, NEAR, and OR. Depending on the search engine or directory, Boolean terms may be recognized by keying the Boolean operator, such as AND and NOT, a symbol such as "+" for AND or "-" for NOT, or they may be assumed, as is the case with AND. Most search engines assume the space before keywords as AND. Using the AND operator with keywords (if required by the search engine) will turn up any material in which all of the terms occur. This can be helpful but tends to produce a lot of results; you may have trouble finding what you need in a long results list.

If that is the case, using the NOT symbol (-) can be very helpful. Suppose that you want to find information on the style of music known as the blues. Entering blues might turn up a lot of documents related to the use of the word blue as a color. To avoid this, you can enter the search term as blues - colors or blues NOT colors, which should cut down on the number of hits relating to blues and color and increase those that concern blues as a style of music.

Using NEAR between two keywords (for example, keyword NEAR keyword) will turn up anything with those two words occurring within 10 words of each other. If you want to find out about concerts in New York, entering concerts NEAR New York will increase the odds that the appearance of the term New York in any document found will be related to concert. Without using NEAR, you will likely find many documents containing the terms concert and New York, but the two terms may come from different parts of the document and have no relationship to each other.

Tips and Tools Using Operators
When using operators, key the operator in all capital letters, not lowercase letters. Some search engines may accept the lowercase format, but the convention is uppercase.

The Boolean operator OR can be used when keying several synonymous terms. Using OR means that the search tool will retrieve all documents containing either term. This is an advantage when you are looking for something that might be categorized under more than one subject. For instance, if you want to learn more about large bodies of water, enter the keywords oceans OR seas. This will produce hits that contain either of these terms. On the other hand, if you enter oceans AND seas, you will find hits containing both of those terms, but not material containing only one of the terms.

Knowing Boolean operators will be helpful, but many search engines and directories have now automated this function with their advanced search options. If you look at the Advanced Search page for Google shown in Figure 1.1, you will see that you need only enter keywords in the correct box rather than having to key Boolean operators. However, knowing Boolean operators can save you time because you won't need to open the Advanced Search page.

Figure 1 Google Advanced Search
google advanced search window

Relational Operators

The second type of operators that will assist your search efforts are known as relational operators, symbols describing the chronological (time-related) relationship between keywords and numbers. The most useful relationship operators are represented by:

< less than
> greater than
<= less than or equal to
>= greater than or equal to
= equal to
Tips and Tools Relational Operators
When keying relational operators, include one space before and after the operator. For example, key artists > 1990, rather than artists>1990.

Suppose you want to find out more information on Jazz, but are not much interested in Jazz before 1980. You could enter Jazz > 1980, which will instruct the search engine or directory to look for any information on Jazz after the year 1980. The results will not be perfect, but you will find that your results list will mostly contain information on Jazz after the year 1980. You can even combine operators, just as you can in mathematical formulas. If you are interested only in a certain period in Jazz history, you could enter Jazz > 1900 < 1930, which will instruct the search engine or directory to look for information on Jazz containing dates between the years 1900 and 1930.

Other Operators

In addition to the relational operators, there are several special characters that will help define searches. For example, the wildcard operator is represented by the dollar sign ($) or asterisk (*). This operator allows you to find all words that begin with a root word or combination of letters that you specify. Entering sail* will find all keywords beginning with sail such as sailors, sailcloth, and so on. One example of how this feature can come in handy is when you do not care if a word is singular or plural. If you want to find information on skiing, you might also be interested in information containing the words skiers, skis, and ski resorts. Using the wildcard operator with ski (ski*) will return hits with all of the ski-related words you are looking for.

The use of quotation marks around a phrase or combination of words instructs the search engine to look for this exact sequence of words. Keying "George W. Bush" will return a results list containing material with that exact sequence of words somewhere in the document. This can be helpful because you can often visualize a sequence of words that would almost certainly appear in the information you are looking for. If you do not place the keywords in quotation marks, the information retrieved will contain documents with your keywords in them, but they may be scattered around the document and meaningless in terms of what you want to find.

Whether or not you capitalize a keyword is usually important. Most search engines are case sensitive, meaning that they distinguish between words beginning with uppercase letters (capitals) and lowercase. If you are looking for information about the country Turkey, this would be very important. If you enter turkey in the search text box, you will find information dealing with the kind of turkeys you eat on Thanksgiving Day. But if you enter Turkey, you will find the results list contains mostly information concerning the country known as Turkey.

Using a period after a word or word stem will limit hits to information with that exact word or word stem. If you want to find material containing the word news, but not newspaper, keying news. will ensure that only material containing the keyword news will appear on the results list.

You also need to be familiar with the search conventions employed by search engines and directories. Do not include the articles and prepositions a, an, the, in, or of in your searches. Search engines index the full text of many files, but the articles are understood. So unless you are searching for an exact title, such as The Declaration of Independence, do not include these words. For example, in a search for the American revolution you would key American + revolution, without the. Table 1 summarizes the conventions and operators described above and can be used for reference.

Table 1 Conventions and Operators for Web Searches
Operator or Convention Purpose Format Example to Key
include both terms; narrows the search nothing
(blank space)
history Jazz
Jazz + history
Jazz AND history
exclude by term; narrows the search -
blues - colors
blues NOT colors
include either term; broadens the search nothing
(blank space)
Jazz history
Jazz, history
Jazz OR history
NEAR find keywords within 10 words of each other keyword near keyword blues NEAR city
> greater than > blues > 1929
< less than < real estate < 100,000
>= greater than or equal to >= blues >= 1960
<= less than or equal to <= blues <= 1960
= equal to = assassinations = 1888
$ * truncate, cut off word stem$, or word stem* sail* (to find sailing, sailors, sailboats, etc.)

“ ”

search for exact phrase “phrase” “The Right Stuff”

. (period) avoid stems word. news. (to prevent newspaper, newscast, newsletter, etc.)
capitalization distinguish between common and proper nouns Use uppercase or lowercase initial Turkey (for the country)
turkey (for the bird)
articles unnecessary unless looking for titles Do not use a, an, the, of, in, etc. The Agricultural Movement
(wrong) Agricultural Movement (right)

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