Boolean operators are search techniques that can narrow your search, broaden your search, or exclude certain terms entirely from your search. They are common across most databases and search engines.
Boolean operators must always be typed using FULL CAPITALISATION. The database will otherwise treat the word in lowercase as part of your search statement. Searching for dogs or cats is not the same as searching for dogs OR cats. Don't make this mistake or your results will be skewed!
AND will narrow your search by telling the database that both words must be included somewhere in the text.
For example, searching for dogs AND cats will show results that only includes both dogs and cats.
OR will broaden your search by telling the database that SOME or ANY of the words must be included somewhere in the text.
For example, searching for dogs OR cats will show results that includes only dogs, includes only cats, or includes both.
OR is especially useful when you are trying to search for a topic that has a lot of synonyms. For example, you might search for disinformation OR "fake news" OR "media manipulation" since these terms are used interchangeably.
NOT will exclude a term entirely from your search.
For example, searching dogs NOT cats will show results that only include information about dogs and nothing about cats.
NOT is especially useful when you are trying to search for a topic that has a lot of subtopics beneath it. For example, you might search for dogs NOT terriers if you are looking specifically for breeds of dogs that aren't terriers.
However, NOT should be used with caution and as a last resort! It may exclude some really great resources that make brief mention of your undesirable term.
Wildcards are symbols that allow you to use root words to search multiple terms at once.
Wildcards will NOT work with subject headings and should only be used for keyword searches. Wildcard symbols can also vary from database to database. Be sure to check which are used in the database's help section before trying to use a wildcard.
However, the two symbols most often used are:
The asterisk (*) is used at the end of a word to represent one or more characters. This is also referred to as truncation. It's most useful when searching for root words with variable endings; for example, searching for econom* will retrieve results that contain economy, economic, economical, economist, economocracy, etc.
The question mark (?) is used inside a word to represent a single character. It's most useful when searching for words that have variable spellings, such as between British and American English; for example, searching colo?r will retrieve results that contain both color and colour.
Proximity operators are a combination of letters and numbers that will allow you to search for words in proximity of one another.
Proximity operators will NOT work with subject headings and should only be used for keyword searches. Operator terms can also vary from database to database. Be sure to check which is used in the database's help section before trying to use a wildcard.
The most common proximity operator is NEAR/n or Nn (the lowercase n representing a number.) Using a proximity operator will search for the two words within those numbers of words from each other in any order. For example, searching for economic N5 records could retrieve results for economic records, records of Canadian economic activity, record years for economic growth, etc. You can choose as few or as many words as you'd like for how close they should be to one another, as it will always search within that number; using 5 will retrieve results as close as 1, 2, 3, 4, and 5 words away.
Boolean operators, wildcards, and proximity operators are most effective when used where subject headings are not or cannot be, such as search engines like Google. They can be combined to make your search strings as broad or narrow as you'd like.