手法を比較

	Collection Overlap Analysis	Conspectus Collection Assessment
分野	Library Information Science	Library Information Science
系統	Process / pipeline	Process / pipeline
提唱年	1998	1995
提唱者	Library collection-management literature; Thomas E. Nisonger (synthesis)	Research Libraries Group (RLG); Western Library Network (WLN); Howard D. White
種類	Set-comparison pipeline for measuring duplication and uniqueness across collections	Structured collection-evaluation pipeline using standardized collecting levels
原典	Nisonger, T. E. (1998). Management of Serials in Libraries. Englewood, CO: Libraries Unlimited. ISBN: 9781563084782	White, H. D. (1995). Brief Tests of Collection Strength: A Methodology for All Types of Libraries. Westport, CT: Greenwood Press. ISBN: 9780313294624
別名	Collection Overlap Study, Holdings Overlap Analysis, Title Duplication Analysis, Collection Comparison Analysis	RLG Conspectus, Conspectus Method, Collecting-Level Assessment, WLN Conspectus
関連	2	2
概要	Collection overlap analysis measures the degree to which two or more library collections hold the same titles, quantifying how much of each collection is shared, how much is unique, and how much in total the collections cover together. By treating holdings as sets and computing intersection, union, and overlap coefficients on matched identifiers such as ISBN, ISSN, or OCLC number, the method turns a vague sense of duplication into reproducible figures. These figures drive concrete decisions: where consortial partners can rely on one another, which titles are uniquely held and so must be preserved, and where duplicate purchasing or storage can be reduced. The technique is a workhorse of cooperative collection development and shared-print retention, summarized across the serials and collection-management literature including Nisonger's syntheses.	Conspectus collection assessment is a structured method for describing and evaluating a library collection subject by subject using a standardized framework of collecting levels. Developed by the Research Libraries Group (RLG) and elaborated by the Western Library Network (WLN), the conspectus partitions the universe of knowledge into subject divisions aligned with Library of Congress or Dewey classification and rates each on a 0-to-5 scale that runs from out-of-scope to comprehensive. Crucially, it separates the existing strength of what a library already holds from its current collecting intensity and its collection goal, producing a profile that supports cooperative collection development and comparison across institutions. Howard D. White's Brief Tests of Collection Strength (1995) gave the method an objective verification layer, using graded checklists to corroborate the otherwise judgmental level assignments.