Classic search interfaces (that is, those used primarily by librarians) forced users to learn the art of crafting search phrases with Boolean operators. To a large extent this was due to the inability of those systems to provide relevancy ranking beyond a "last in, first out" approach. Thankfully, Evergreen, like most modern search systems, supports a rather sophisticated relevancy ranking system that removes the need for Boolean operators in most cases.
By default, all terms that have been entered in a search query are joined with
an implicit AND
operator. Those terms are required to appear in the designated
fields to produce a matching record: a search for golden compass will search
for entries that contain both golden and compass.
Words that are often considered Boolean operators, such as AND, OR, and
NOT, are not special in Evergreen: they are treated as just another search
term. For example, a title search for golden and compass
will not return the
title Golden Compass.
However, Evergreen does support Boolean searching for those rare cases where you might require it, using symbolic operators as follows: