BOOLEAN LOGIC APPLIED TO ONLINE SEARCHING Critical Thinking
BOOLEAN LOGIC APPLIED TO ONLINE SEARCHING Critical Thinking & Problem Solving © Janet Tillman/The Master’s College, 2002, permission is granted for non-profit educational use; any reproduction or modification should include this statement.
Boolean Algebra Science of Logic based on Mathematics in that it works with logical rather than numeric relationships Algebra x and y = numerical values Boolean algebra x and y = classes of objects; truth values Boolean Logic is a form of algebra in which any variable can have a logical value of TRUE or FALSE. Applications include mathematical logic, digital logic, computer programming, set theory, and statistics. Boolean Logic is crucial to the development of twentieth century computer programming because it fits nicely with the binary numbering system, in which each bit has a value of either 1 or 0.
Venn Diagram A fundamental application of Boolean logic is the organization of concepts into sets. Set A Set B
= INTERSECTION A B U U Set A Set B Intersection of Set A and Set B
U = UNION A U B Set A Set B Union of Set A with Set B
U Set A A B UNION Set B ? INTERSECTION Set A A U B Set B
BOOLEAN OPERATORS • AND • OR • NOT Set A Set B
BOOLEAN OPERATORS • AND Messiah AND Christ - Requires that both terms be in the results - Can be thought of as BOTH -Often represented as “All of these” - Used for combining differing concepts - Narrows the search • the INTERSECTION of two sets
BOOLEAN OPERATORS • OR Messiah OR Christ - Broadens the search - Used to find one term OR another - Can be thought of as EITHER -Often represented as “Any of these” - Used to search synonymous/closely related terms • the UNION of two sets
BOOLEAN OPERATORS • NOT -Narrows a search -Used to eliminate records -Exercise extreme caution; needed concepts may be eliminated unintentionally Messiah Christ Messiah NOT Christ
BOOLEAN APPLIED
a U b c U a b c
a U b c U a b c
a OR b AND c a b c
Messiah OR Christ AND Jesus Christ Messiah Jesus
Messiah OR Christ AND Jesus Christ Messiah Jesus
Messiah OR (Christ AND Jesus) Christ Messiah Jesus
(Messiah OR Christ) AND Jesus Messiah OR Christ AND Jesus Messiah Jesus Christ
(Messiah OR Christ) AND Jesus Christ Messiah Jesus
Messiah OR Christ OR Jesus Messiah AND Christ AND Jesus Messiah OR Christ AND Jesus
Messiah OR Christ OR Jesus Christ Messiah Jesus
Messiah AND Christ AND Jesus Christ Messiah Jesus
(Messiah OR Christ) AND Jesus Christ Messiah Jesus
LOGICAL OPERATORS • Limiting Operators -Peer Reviewed -Proximity -Phrases -Field -Truncation, Wildcard -Date -Type of Document -Language -Number of Pages
LIMITING/EXPANDING OPERATORS • Phrases Typical symbol used “” • Truncation/Wildcards Typical symbols used * ? ! -“physical therapy” -plurals -“educational technology” -variant endings: ed, es, ing; • Related Terms/Topics banks, banking, bankruptcy -work, job, career, -variant spelling: -thought, think, women/woman; color/colour; thinking encyclopedia/encyclopaedia; judgment/judgement
LIMITING OPERATORS • Date • Type of Document -Specific date -Before < -After > -Range -Article -Book Review • Language -English -French -Chagatai -Thesis/Dissertation -Proceedings -Manuscripts
Fields Library Catalog Author/Creator Title Subject ISBN SCIENCE BUSINESS Super Taxa Gene Symbol Molecular Sequence Slogan Company Name INTERNET Media Types (Java, Images, Script, etc. ) Page Depth Location/Domain NYSE Symbol PERIODICALS Scholarly/Peer Reviewed Citation/Abstract References cited
- Slides: 27