- Boolean Logic Combining search statements using Boolean operators.
Boolean Logic Combining search statements using Boolean operators.
Slide 1Boolean Logic Combining search statements using Boolean operators Slide 2 Bolean Logic2 Boolean searching - OR In database searching OR expands a search by broadening the set. It is often used to combine synonyms or like concepts. Example 1. Use Boolean logic to describe an ice cream lover with global tastes (the coloured area) Strawberry OR chocolate OR vanilla Slide 3 Bolean Logic3 Boolean searching - AND In database searching AND narrows a search. It is often used for linking together different concepts. Example 2. Use Boolean logic to describe an ice cream lover who only eats ice cream which combines 3 flavours at the same time e.g. Neopolitan ripple (the coloured area) Strawberry AND chocolate AND vanilla Slide 4 Bolean Logic4 Boolean searching - NOT In database searching, NOT is used to get rid of an unwanted concept. Example 3. Use Boolean logic to describe an ice cream lover who wont eat chocolate (the coloured area) (Strawberry OR vanilla) NOT chocolate But BEWARE! you may also exclude relevant articles. Slide 5 Bolean Logic5 Boolean searching - PARENTHESES Parentheses define the order in which the concepts are processed. AND takes priority OR is processed last HAMBURGERSEGGS SALMONELLA Use parentheses to ensure terms are processed as intended Slide 6 Bolean Logic6 Some examples Example 4: Find information on the influence of eggs on salmonella food poisoning caused by hamburgers salmonella AND hamburgers AND eggs = food poisoning caused by both together (hamburgers OR eggs) AND salmonella = food poisoning caused by either hamburgers OR eggs AND salmonella = Do you want eggs and gastro with your hamburger, or would you rather have fries? (hamburgers AND salmonella) NOT eggs = = only food poisoning caused by hamburgers (removing the confounding effect of having eggs at the same time) Slide 7 Bolean Logic7 A more complex example Use Boolean logic to describe: Women who have breast cancer but have never smoked Women who have breast cancer and who are EX- smokers Breast Cancer Ex-smokersWomen Smokers Slide 8 Bolean Logic8 Women who have breast cancer but have never smoked = (women AND breast cancer) NOT smokers A more complex example Ex-smokersWomen Breast Cancer Smokers Ex-smokersWomen Slide 9 Bolean Logic9 Breast Cancer Smokers Ex-smokersWomen Women who have breast cancer and who are EX- smokers = women AND breast cancer AND ex-smokers A more complex example Slide 10 Bolean Logic10 Breast Cancer Ex-smokersWomen Smokers Men who have breast cancer and who currently smoke = (men AND breast cancer AND smokers) NOT ex-smokers Another complex example Slide 11 Reference Reference: Henderson J & Strickland J. Ithaca College Library Research Guide: Boolean Logic. Accessed at: http://www.ithacalibrary.com/sp/subjects/boolean on January 24, 2010 http://www.ithacalibrary.com/sp/subjects/boolean Bolean Logic11