E-LEARN: Search Strategies


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Every search system offers a variety of features and special search techniques, and rarely are any two systems searched exactly the same way. There are, however, some common search strategies that you can use for databases and other systems.

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E-LEARN: Search Strategies

  1. 1. Search StrategiesEvery search system offers a variety offeatures and special search techniques. Rarelyare any two systems searched exactly thesame way.Many systems offer help screens that providevaluable assistance with frequently usedsearch strategies, as well as very specializedtechniques, such as case sensitivity.Often the only way to use the search systemsefficiently is to access the help provided.
  2. 2. There are, however, some common searchstrategies that can be utilized for databasesand other systems. These include:• Boolean Operators• Nesting• Truncation• Controlled Vocabulary
  3. 3. Search Strategy #1 - Boolean OperatorsOver 150 years ago, George Boole, an Englishmathematician, developed Boolean Algebra.This brand of mathematics has been applied toset theory, probability, and computer circuit design. Itsmost important application for libraries has been its usein search strategies. We use "logical" operators tocombine concepts in order to retrieve informationfocused on a topic of interest. Two or more conceptscan be paired to satisfy research needs, and relatedterms can be grouped to express a single concept.
  4. 4. Boolean Operators - use ofAND, OR, XOR, NOT or other logical operatorsfor expanding or narrowing a searchstatement.An example would be using "global warmingOR greenhouse effect" to retrieve items thatpertain to either of those concepts.Another example would be to search "careerAND engineering" to retrieve items thatpertain to something about job opportunitiesfor engineers.
  5. 5. What Boolean is NOT:• Proximity Operators - such as same, with, near, adj• Relational Operators - such as >, <, or + values• Like most Internet searching - relevancy ranking
  6. 6. AND OPERATOR• used to narrow focus of research• results of search will contain not only one concept but also the other• intersection of setsExample: cars AND autos
  7. 7. OR OPERATOR (inclusive)• Used to expand a search or widen its scope• results will have at least one of the concepts• may retrieve results that contain all identified concepts• range searching and truncation are forms of OR-ingExample: cars OR autos
  8. 8. XOR OPERATOR (exclusive)• Used to expand a search or widen its scope• results will have one of the concepts, but not bothExample: cars XOR autos (not both)
  9. 9. NOT OPERATOR• eliminates results which include a particular search• sometimes is called BUT NOT• needs to be used very cautiouslyExample: autos NOT cars
  10. 10. Search Strategy #2 - Nesting• Nesting - the use of parentheses or other punctuation to group related concepts together to clarify the order in which a search is executed.• The grouped concepts will be searched first, as a mathematical question.
  11. 11. Example:(cats OR feline) AND (veterinary OR medicine)
  12. 12. Search Strategy #3 - TruncationTruncation - the use of a symbol to indicatea search for a term containing a certainnumber of specific characters, after whichany character or characters are acceptable.A truncation symbol tells the computer tolook for any character(s) in a spot. Itfunctionally "OR"s terms together.
  13. 13. Examples:seagrass* or sea grass* (seagrass orseagrasses or sea grass or sea grasses)librar* (librarian or librarians orlibrarianship or library or libraries)
  14. 14. Caution:• Sometimes truncating a word can bring irrelevant results (also called "false drops").Example:• If a student was searching for information on "artificial intelligence", he or she might choose to truncate the word "intelligence" in the manner below:• OOPS - artificial in? CAUTION: Think of the results you might get.
  15. 15. Some truncation symbols take the place ofone character within the word, such as in"behavio?r" or "wom*n" while others canreplace any numbers of characters.This is sometimes called wildcarding.
  16. 16. Some examples of truncation symbols:• * (lots of periodical databases)• ? (a classic - from Dialog searching days -- Dialog was the first on-line database, circa 1972.)• ! (less common, usually special, such as a single character)• $ (Our Library Catalog)• # (fairly uncommon, used in STN International and the Scientific and Technical Information Network databases)
  17. 17. • Truncation saves keyboarding, therefore time, errors(!), thinking, and sometimes money when used in "for-fee" databases, which charge users by the minute.• Some databases "assume" truncation. This is called autostemming.
  18. 18. Search Strategy # 4 - ControlledVocabularyControlled Vocabulary - use of terms orsubject headings that have been previouslyidentified as common or standard within acertain field
  19. 19. Some concepts are common acrossdisciplines; however, certain specializedterms may be required to retrieve desiredresults within a specific database(controlled vocabulary).Many search systems offer this kind ofspecialized searching, as well as lessspecialized keyword searching.
  20. 20. Some examples include the termsfrequently used to index psychologyresources, which are found in theThesaurus of Psychological IndexTerms, and the vocabulary often used inengineering literature, which can be foundin Ei Thesaurus.
  21. 21. The Library of Congress Subject Headingsvolumes provide the specialized terms ofmost academic librarycollections, including the library catalog ofFlorida Tech.
  22. 22. Help!When you first accessany type of database, itwill be to youradvantage to scrollthrough the Help!topics.Doing so familiarizesyou with the searchstrategies specific tothat particulardatabase.
  23. 23. Boolean operators: NOTNOT can narrow yoursearch, taking out thebad – and sometimesthe good.
  24. 24. Boolean operators: ANDAND is anotherBoolean operator youmight choose to use.You would use AND ifyou wish to narrowyour search torecords that containtwo or more specifiedkey terms.
  25. 25. Boolean operators: ORAn additionaloperator is OR. UsingOR tells the computerto expand yoursearch to either ofthe concepts youhave listed.
  26. 26. Practice!You type the searchterm INSTRUCTION intothe Library catalog.The resulting numberof entries returned is1533. That is anenormous number ofrecords to sort through.How would you narrowyour search?
  27. 27. PracticeOne way is to add anadditional search term.Think about exactly whattype of information relatedto instruction you wish tofind.You are interested in theuse of TECHNOLOGY inINSTRUCTION. How wouldyou combine these terms?Think about which of theBoolean operators wouldbe the best to use.
  28. 28. PracticeUsing AND tells the computer to search for theterm INSTRUCTION and the term TECHNOLOGY.Now, youve narrowed your search results down;only 245 records were returned. However, youmay be missing a number of relevant records.
  29. 29. PracticeSlightly expand yoursearch by addinganother relevantterm, COMPUTERS.You are really lookingfor how computers areaffectinginstruction, but realizethe term TECHNOLOGYis synonymous with theterm COMPUTER.
  30. 30. PracticeOne way to use bothterms is includingthe Booleanoperator OR.
  31. 31. PracticeWhen you run this search strategy, youreceived 15,952. Thats even more than whatyou retrieved with your original result. Whywere so many records returned?The computer searched for the termsINFORMATION AND TECHNOLOGY togetherOR anything on the term COMPUTER. Thecomputer did not combine the termsappropriately. To correct this mistake, youwould want to use NESTING ( ).
  32. 32. PracticeRemember, NESTINGtells the computerthat groupedconcepts will besearched first, as in amathematicalequation.Thissearch, INSTRUCTION AND(TECHNOLOGY ORCOMPUTER), yields574 records from theLibrary catalog.
  33. 33. PracticeThese are good search terms and use ofsearch strategies, but you could havemissed a few additional records that haveother forms of the word COMPUTER.For example, you may have missed recordscontaining the terms "computerized" or"computers." What would you use toinclude such records?
  34. 34. PracticeYou can expand yoursearch by usingTRUNCATION.Each system uses aspecific character toexpress this searchstrategy. In the LibraryCatalog, we use the $sign. ProQuest uses the *for its truncation symbol.How would you find outwhat symbol is used inany given database?
  35. 35. PracticeWhen you Truncatethe term COMPUTERand run your searchagain, you retrieve583 records.So, you broadenedyour search onlyslightly;however, you haveincluded all relevantterms.
  36. 36. PracticeYou are probablythinking that 583 isstill a lot of records toreview. Lets not forgetour last searchstrategy: CONTROLLEDVOCABULARY.
  37. 37. PracticeThe Library ofCongress SubjectHeadings (LCSH)volumes provide thespecialized terms formost academiclibrarycollections, includingthe library catalog ofFlorida Tech.
  38. 38. PracticeYou look in the LCSH tosee if there is a narrowerterm for "technology."The term "educationaltechnology" is listed, soyou decide to include itin your search.Of course, the Booleanoperator AND is neededto complete the searchstring.
  39. 39. PracticeThis searchstring, INFORMATION AND(TECHNOLOGY ORCOMPUTER*) ANDEDUCATIONALTECHNOLOGY, retrieves 112records, which is areasonable number.
  40. 40. PracticeTo limit your search to more recentpublications, you may choose to narrowthe search by year in the Library catalog.Limiting the search to items dated 1997 to2008 will retrieve 31 records.
  41. 41. PracticeUse what you learned aboutHELP, BOOLEAN, TRUNCATION, NESTING, and CONTROLLED VOCABULARY from thishuman search string example to helplocate information resources for your nextresearch topic.