Stop Words and Boolean Searching Think of the Library as one large database, a collection of information. There are items about medicine, nursing, and occupational therapy. There are items with every imaginable word in the title. There are items by a wide variety of authors.
All items belong to more than one subset, however.
Every item in the library has at least one title, author, and subject heading. It is possible to search for books that fit into more than one subset. For example you can do a search for items that have the word cancer in the title. This set is represented by the blue circle. You can also do a search on items whose authors' last name is Smith.