资讯检索策略与技巧.ppt

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1、資訊檢索策略與技巧黃慕萱，Chap.6Harter，Chap.71檢索策略v.s.檢索技巧最早為軍方用語各家看法1979，MarciaBates，”InformationSearchTactics”Hartly如何避免找到不相關文章的方法處理找到過多或過少相關文章的可能對策Palmer指分區組合檢索和引用文獻滾雪球法Pao指布林邏輯、引用文獻及機率檢索策略檢索策略(searchstrategy)針對一檢索問題之通盤考量或全面性之規劃如分區組合檢索法、引用文獻滾雪球法….等檢索技巧(searchheuristics)為完成特定目的所

2、採取的行動2Briefsearch簡易檢索最常見的檢索方式快速簡單fastandinexpensive但常是低recall，低precision適用主題明確想瞭解資料庫製作者所使用的敘述語和索引詞彙確認書目資料已知書名、作者等3BuildingBlocksSearch分區組合檢索法亦有人稱為“blockbuilding”或“buildingblock”檢索方式將索引問題分解成數個主題層面(facets)確定主題層面間的關係通常facets間的關係為”AND”，出現”OR”或”NOT”的情況較少找出可代表各主題層面的檢索詞彙利用布

3、林邏輯”OR”做聯集，以求完整性使用率最高，早期參考晤談表格常依此設計4BuildingBlocksSearchStrategy--1/4ConductreferenceinterviewsFormulatesearchobjectivesHighrecallHighprecisionModeratelevelsofrecallandprecisionSelectdatabase(s)andsearchsystemIdentifymajorconceptsorfacetsandtheirlogicalrelationshipswi

4、thoneanother5BuildingBlocksSearchStrategy--2/4IdentifysearchstringsthatrepresenttheconceptsWordsFull-textphrasesPiecesofwordsDescriptorsIdentifiersCodesNon-semanticbibliographiccharacteristics非主題相關的欄位，如資料類型、語言、年代等包括同義詞、類同義詞、狹義詞、相關詞fieldstobesearched6BuildingBlocksSear

5、chStrategy--3/4Foreachdistinctfacetofthesearch,asetofpostingswillbecreatedforeachsearchstringwithinthatfacet.ThesetsarethencombinedintoasinglesetrepresentingthatfacetusingBooleanORFollowingsetp#6,thefacetssetsthemselveswillbecombinedwithBooleanANDandNOTPlanalternative

6、s7BuildingBlocksSearchStrategy--4/4FormulatetheinitialstatementsofthesearchinthecommandlanguageofthesystemLogonandputthesearchtothesystemEvaluatetheintermediateresultsIterateUsetheinteractivefeaturesofthesystemtocarryoutsearchheuristicstactics,maneuvers,strategies,tr

7、icks,devices,approaches,totrytoimprovesearchresults8BuildingblocksapproachFacetAFacetBTermA1ORTermA2OR………..TermApTermB1ORTermB2OR………..TermBqFactCTermC1ORTermC2OR………..TermCrAnswerSetBooleancombinationoffacets(AND,OR,NOT)9BuildingBlockssearchsampleFacet1Facet2Facet3Face

8、t4Facet5RISKMEASUREMENTRISKAVERSIONBEHAVIORALDECISIONTHEORYINSURANCEriskmeasurementassessmentchoicedecisionoutcomeriskaversi