Search Logic Viewing Results Labs 3 4 Dr Dania Bilal IS 530 Fall 2007 Boolean Logic Search logic is based on Boolean logic Boolean logic is a system for logical operations Based on George Boole An English mathematician Boole was the first to define an algebraic system of logic in mid 19th century Boolean logic has many applications in electronics computer hardware and software and database searching Boolean Logic Database Searching Boolean logic is used to organize concepts together in sets When searching any IR system e g online catalog database search engine using keywords and or a combination of keywords and query processing is based in part on Boolean operators Boolean Operators AND for narrowing search results Ex strawberry and vanilla and chocolate OR for expanding search results Ex strawberry or vanilla or chocolate NOT for narrowing search results by eliminating unwanted concepts from search results Ex strawberry or vanilla not chocolate strawberry or vanilla not chocolate Boolean Operator OR Used to build up concepts Helpful for Synonyms or equivalent terms Ex occupations or jobs Spelling variations Ex harbor or harbour Related terms Ex brain injury or head injury Venn Diagram AND Strawberry and vanilla and chocolate Venn Diagram OR Strawberry or vanilla or chocolate Venn Diagram NOT strawberry or vanilla not chocolate Beyond Boolean Truncation Truncation is used to expand search results by stemming a word or concept at its root to obtain results with the variant forms of names and or words obtain variant spellings is the symbol used in Dialog See Pocket Guide p 6 for use of multiple truncations Beyond Boolean Nesting Nesting is a technique used to group similar terms or terms that have relationships together to increase search results while forcing the retrieval software to change its order of processing of the Boolean operators based on their strengths Boolean Strengths Boolean operators are executed based on their strengths from highest to lowest NOT AND OR Viewing Search Results Type t command is used to view search results Results can be viewed based on Nine Dialog system defined formats and or See Workbook chap 4 Other format s are user defined based Based on field tags rather than a standard format such as ti ab au py Found in bluesheets Type Command Tags are found in a database bluesheets Type command is composed of four parts t set no format record no s Example t s1 3 1 5 system defined format 3 Example t s1 au ti ab 1 5 user defined format with author title and abstract Display Command Display or DS allows viewing search sets or search history Differs from Type command Typing DS will display all search terms and sets performed in a search Nesting Search technique used to group similar terms or terms that have relationships together to increase search results Used to force retrieval software to change its order of processing of the Boolean operators based on their strengths Results in lower recall but higher precision Nesting Used when more than one Boolean exists in search query Effectiveness based on how well you build blocks or nests for terms in a query Use search grid or sheet for building concepts then connect with appropriate operator Boolean Other Features in Google Class Activity Work in a group Examine how the Boolean truncation and search parameters covered in these slides are used in Google You may want to check the Advanced features in Google and how to use Google You have 15 minutes Proximity Searching Overview Proximity operators used to Increase precision of search results Avoid false drops or false hits that result from using keyword searching Employed more in proprietary databases than in Web search engines Proximity in Dialog W N L S F There are additional proximity operators that we will cover in class soon Guided Searching Based on collaboration between IU faculty students and staff and system developers such as web search engines ChaCha Software developed by Indiana University alumni Building alliance with Google and other engines IU will offer human aided academic search services through ChaCha students faculty and staff ChaCha specializes in machine based searches augmented by knowledgeable human guides