Tefko Saracevic, Rutgers University 1 Practice for logical operators Boolean search statements and Venn diagrams

Tefko Saracevic, Rutgers University 2 Exact match - Boolean search You retrieve exactly what you ask for in the query: –all documents that have the term(s) with logical connection(s), and possible other restrictions (e.g. to be in titles) as stated in the query –exactly: nothing less, nothing more Based on matching following rules of Boolean algebra, or algebra of sets –‘new algebra’ –presented by circles in Venn diagrams

Tefko Saracevic, Rutgers University 3 Boolean algebra & Venn diagrams Four basic operations: 123 AB A alone. All documents that have A. Shade 1 & 2. E.G. apples 123 AB A AND B. Shade 2 apples AND oranges 123 AB A OR B. Shade 1, 2, 3 apples OR oranges 123 AB A NOT B. Shade 1 apples NOT oranges

Tefko Saracevic, Rutgers University 4 Venn diagrams … cont. Complex statements allowed e.g A B C (A OR B) AND C Shade 4,5,6 (apples or oranges) AND Florida (A OR B) NOT C Shade what? (apples or oranges NOT Florida

Tefko Saracevic, Rutgers University 5 Directions for exercise Slide 7 provides a Venn diagram with numbered sets and a number of search statements –for each statement shade the appropriate set or sets –e.g. for (A OR B) AND C the sets are 4, 5, 6 Slide 8 is for practice Slide 9 has the answers –BUT NOTE: one of the answers is WRONG! Which one?

Tefko Saracevic, Rutgers University 6 Order of operations Rules for the order in which operations are done effect the answer - so follow them Dialog order of operation is: 1. First are done all operations that are in parentheses, then: 2. (W), (N), (S), (L), or (F) 3. NOT 4. AND 5. OR e.g. for A OR B AND C, first is done B AND C, and then A OR the results of B AND C, thus this is the same as A OR (B AND C)

Tefko Saracevic, Rutgers University 7 Venn diagrams AB C 1. A AND B 2. A OR B 3. A OR B AND C 4. (A OR B) AND C 5. A AND B NOT C 6. A AND (B NOT C) 7. (A AND B) NOT C 8. (A NOT B) AND C 9. A NOT (B AND C) 10. A NOT B AND C 11. A AND (B OR C) 12. A AND B OR C 13. A OR (B AND C) 14. A OR B OR C 15 A AND B AND C

Tefko Saracevic, Rutgers University A B C Use for exercise & shading

Tefko Saracevic, Rutgers University 9 1. A AND B2,5 2. A OR B1,2,3,4,5,6 3. A OR B AND C1,2,4,5,6 4. (A OR B) AND C4,5,6 5. A AND B NOT C2 6. A AND (B NOT C)2 7. (A AND B) NOT C2 8. (A NOT B) AND C4 9. A NOT (B AND C)6 10. A NOT B AND C4 11. A AND (B OR C)2,4,5 12. A AND B OR C2,4,5,6,7 13. A OR (B AND C)1,2,4,5,6 14. A OR B OR C1,2,3,4,5,6,7 15 A AND B AND C AB C Venn diagrams: solutions p.s. one of them is wrong!