Constructing a search string: keywords and operators
Adding special characters and words, known as operators,
gives the search engine more precise instructions on how to search
and so provides you with more relevant results.
The choice of operators to use depends on the nature of the keywords
you have identified:
- A proper name or a distinct phrase
If you have
identified a distinct phrase, you will want the search
engine to find documents that contain only that exact phrase. The
common way to specify a phrase is to enclose it in double
eg "native american"
- Words with multiple meanings and contexts
To make your search specific you need to search for documents
that include every one of several words. To do this use the Boolean
AND operator. Search
engines commonly use this operator by default, so often you
do not need to put
this operator in the search string.
For example: children AND poverty AND Africa.
Often a document will only
be relevant if two or more of your keywords are close
one another. You can specify this in your search string by using
For example: william
NEAR gladstone would match William Gladstone, William Ewert Gladstone,
William E Gladstone and Gladstone, William Ewart.
- Synonyms and spelling variations
ensure the search engine retrieves documents with any one
of your variants,
For example: "red
OR "native american"
Some spelling variations
can be accounted for by assigning the wildcard
operator to allow variation in one character.
- Words with many possible endings
To tell a search
engine to search for all the words derived from a common root, use
For example: femin* will match feminism, feminist and feminine.
- Words you want to exclude to prevent irrelevant results
To ensure any documents including such a word are excluded
from your search, use the Boolean
AND NOT operator.
For example: "special education" AND NOT hyperactivity
Internet search engines do not usually support as many
search features as the search engines in subscription databases. For
truncation is not commonly available in Internet search engines. Check
the help pages for any search engine you use
features are included, and how you can use them. You may find the search
engine features chart at Search Engine Watch a useful guide to
the operators supported by popular Internet search engines.