- Boolean Operators

Are your search terms ordinary words that can have several interpretations or contexts?

Using the search operator “AND”

With AND you broaden your hits to include all the words that are in your search. If there is a menu in the search service, you can choose “Boolean phrase” and write AND between the words. In some menus you can choose “Boolean AND” and need only to write the search words.

Example:
You want to get hits that include the words “Swedish”, “Minnesota”, and “1800”
Search for: Swedes AND Minnesota AND 1800

In some search services, you can make the same demands by writing a plus sign before the words that are to be included. If there is a menu, you can select all the required words and then you do not need a plus sign.
Search for: +Swedes + Minnesota + 1800

Do you expect to get many hits that are not relevant?

Using the search operator “NOT”

With NOT (sometimes written AND NOT) ), you limit your search so that the documents that contain certain words are excluded. In a menu you choose “Boolean phrase”.

Example:
You want to find documents that contain the word “emigration” but want to exclude documents that contain the word “America”.
Search for: emigration NOT America

Using a minus sign in front of the word or phrase works in a similar way in certain search services.
Search for: emigration -America

ATTENTION: With a NOT search you risk missing relevant material wherever the excluded word occurs.

Do you want to include synonyms, different spellings or the same term in different languages?

Using the search operator “OR”

With OR you can structure your search to include documents that contain any of the words you have selected. In the menu, you choose the “Boolean phrase”.

Example:
You want to find documents that contain any of the words emigration or resettlement in combination with either of the words statistik or statistics.
Search for: (emigration OR resettlement) AND (statistik OR statistics)

In a search service where you can use plus and minus to specify your search criteria, you can achieve an OR-search by leaving a dash between the words. In the menu you choose “Any of these words”.
Search for: Nordamerika "North America"