資訊檢索策略與技巧-資料下載頁
2024-10-11 09:07本頁面
【導(dǎo)讀】處理找到過多或過少相關(guān)文章的可能對策。指分區(qū)組合檢索和引用文獻(xiàn)滾雪球法。指布林邏輯、引用文獻(xiàn)及機(jī)率檢索策略。針對一檢索問題之通盤考量或全面性之規(guī)劃。為完成特定目的所採取的行動。最常見的檢索方式。但常是低recall，低precision. 想瞭解資料庫製作者所使用的敘述語和索引詞彙。已知書名、作者等。亦有人稱為“blockbuilding”或“buildingblock”。將索引問題分解成數(shù)個主題層面。確定主題層面間的關(guān)係。通常facets間的關(guān)係為”AND”，出現(xiàn)”O(jiān)R”或”NOT”的情況。找出可代表各主題層面的檢索詞彙。利用布林邏輯”O(jiān)R”做聯(lián)集，以求完整性。使用率最高，早期參考晤談表格常依此設(shè)計。非主題相關(guān)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(guān)詞
【正文】 publication 31 Questions to ask in low precision—1/2 ? Am I in the correct database? ? Have I underspecified the search problem? ? Do I need to disambiguate a concept of the problem? ? Have I used Boolean logic correctly? ? Have I include vague or ambiguous terms, or terms that are too generic? 32 Questions to ask in low precision—2/2 ? Should I restrict search terms to elements of a controlled vocabulary? ? Where the proximity specifications too loosely placed on the search terms? ? Are false drops resulting from concepts having an unintended relationship with one another? ? Has a search term been truncated too severely? 33 Heuristics for Increasing Precision 1/2 ? Delete near synonyms and potentially ambiguous terms ? Use more specific terms to represent concepts ? Use controlled vocabulary terms if a concept is precisely represented by them。 delete controlled vocabulary terms that do not describe a concept precisely ? If multiple meaning does not appear to be a major problem, search natural language terms that represent the concepts of interest precisely 34 Heuristics for Increasing Precision 2/2 ? If none of the above conditions applies, search fewer subject fields, deleting fields in the approximate order。 full text, abstract, title, identifier, and descriptor ? Add additional facets with AND and NOT ? Decrease term truncation ? Use more restrictive proximity operators ? Add restrictions to the formulation, ., by date of publication, type of publication, language, etc. 35 Personal Heuristics—1/2 ? Be flexible。 stay loose。 be willing to look at a search in more than one way. Avoid rigidity in thought and action. ? Browse samples of retrieved citations to assess relevancy. ? Browse samples of retrieved citations to generate additional search terms. ? Be heuristic, interactive. Don’t do “fast batch” searching. 36 Personal Heuristics—2/2 ? Evaluate one’s own work critically. ? Always be skeptical of search output. ? A mindless faith in controlled vocabularies is not always justified. Be critical of the adequacy of artificial languages for the representation of concepts in documents.
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