手法を比較

	Controlled Vocabulary Indexing	Metadata Quality Assessment
分野	Library Information Science	Library Information Science
系統	Process / pipeline	Process / pipeline
提唱年	2005	2004
提唱者	ANSI/NISO Z39.19; Elaine Svenonius	Thomas Bruce & Diane Hillmann; Jung-ran Park & Yuji Tosaka
種類	Indexing pipeline using a controlled vocabulary	Measurement pipeline for metadata quality
原典	NISO. (2005). ANSI/NISO Z39.19-2005 (R2010): Guidelines for the Construction, Format, and Management of Monolingual Controlled Vocabularies. Baltimore: NISO.	Bruce, T. R., & Hillmann, D. I. (2004). The Continuum of Metadata Quality: Defining, Expressing, Exploiting. In D. I. Hillmann & E. L. Westbrooks (Eds.), Metadata in Practice (pp. 238-256). Chicago: ALA.
別名	Subject Indexing, Controlled Indexing, Assigned Indexing, Vocabulary-Controlled Subject Indexing	Metadata Quality Evaluation, Metadata Quality Measurement, Metadata Assessment, Digital Repository Metadata Evaluation
関連	3	3
概要	Controlled vocabulary indexing is the process of representing what a document is about by assigning preferred terms drawn from an established controlled vocabulary or thesaurus, rather than from the document's own free-text words. ANSI/NISO Z39.19 codifies the practice: the indexer first performs conceptual analysis to determine a document's aboutness, then translates each concept into the vocabulary's preferred term, choosing how many concepts to capture (exhaustivity) and how finely to express each (specificity). Elaine Svenonius's account of subject languages explains why this controlled translation matters — it eliminates the synonymy and homonymy of natural language so that one concept is always indexed under one term. Done consistently, controlled vocabulary indexing gives a collection reliable, predictable subject access that free-text search alone cannot guarantee.	Metadata quality assessment is the systematic measurement of how good a collection's descriptive metadata is for its intended purposes. Thomas Bruce and Diane Hillmann's influential framework defined quality along a continuum of dimensions — completeness, accuracy, conformance to expectations, logical consistency and coherence, timeliness, accessibility, and provenance — and argued that quality must be defined relative to use, then expressed and exploited. Jung-ran Park and Yuji Tosaka surveyed how digital repositories operationalize the three most widely accepted criteria — accuracy, completeness, and consistency — into concrete control mechanisms. Assessment turns these dimensions into measurable indicators, scores records and collections against them, and produces diagnostics that pinpoint where metadata falls short, so that interoperability, discovery, and trust can be improved.