Let's create an OPAC where:
- The term "duck" is found exclusively in 200 records
- The term "blind" is found exclusively in 50 records
- The terms "duck and blind" are found together in 15 records
- The term "tiger" is found exclusively in 100 records
- The terms "tiger and blind" are found together in 25 records
- The terms "tiger and duck" are never found together.
Search Statements
- Select: "duck" = 200 + 15 = 215 records
- Select: "blind" = 50 + 15 + 25 = 90 records
- Select: "duck OR blind" = 200 + 50 + 15 + 25 = 290 records
- Select: "duck NOT blind" = 200 + 25 = 225 records
- Select: "duck AND blind" = 15 records
- Select: "tiger" = 100 + 25 = 125 records
- Select: "tiger OR blind" = 50 + 15 + 100 + 25 = 190 records
- Select: "tiger NOT blind" = 100 records
- Select: "tiger AND blind" = 25 records
Finally, consider the following:
- Select: "tiger AND duck AND blind" = 0 records
Page creator: J. Stephen Downie
Page created: 27 October 1997
Page updated: 28 October 1997