Metadata

History and Definition of Metadata - Metadata was used in traditional card catalogs in libraries until the 1980s - In the 2000s, metadata standards were developed for digital data - MIT's Center for International Studies experts noted the first description of metadata for computer systems in 1967 - Unique metadata standards exist for different disciplines - Government organizations in many countries store metadata about various activities, such as emails and web pages - Metadata means data about data - It provides information about various aspects of the data - Examples of metadata include the purpose, time and date of creation, and file size - Metadata can describe different types of data, such as digital images and text documents - Metatags were used as a factor in web searches until the late 1990s Types and Purposes of Metadata - Structural metadata describes the structure of database objects - Guide metadata helps humans find specific items through keywords - Ralph Kimball categorizes metadata into technical, business, and process metadata - Metadata can be classified as structural/control metadata and guide metadata - There are specialized models to specify different types of metadata - Metadata helps users find relevant information and discover resources - It organizes electronic resources and provides digital identification - Metadata allows resources to be found by relevant criteria and brings similar resources together - It distinguishes dissimilar resources and provides location information - Metadata is used for traffic analysis and mass surveillance in telecommunication activities Metadata Management - Metadata can be stored and managed in a metadata registry or repository - Without context and a point of reference, it may be difficult to identify metadata - Metadata can be perceived differently based on the context it is presented in - The term 'metadata' was coined in 1968 by Philip Bagley - Various disciplines have adopted their own specific explanations and uses of metadata Metadata Standards and Schemata - International standards, such as ISO/IEC 11179, apply to metadata - ANSI and ISO are working on standardizing metadata and registries - ISO/IEC 11179 is the core metadata registry standard - Part 1 and Part 3 of ISO/IEC 11179 provide the framework for metadata registration - The new edition of Part 1 aligns with the current edition of Part 3 and extends the MDR - Metadata schemata can be hierarchical, linear, or planar - Hierarchical schemata have parent-child relationships between metadata elements - Linear schemata classify elements according to one dimension only - Planar schemata classify elements according to two orthogonal dimensions - Hypermapping is used to enable display and view of metadata in complex schemata Specialized Metadata and Applications - Statistical data repositories have specific metadata requirements - Metadata describes the source, quality, and statistical processes used to create the data - Metadata validation and improvement are important to the statistical community - Metadata helps identify resources suitable for users with specific needs - More work is needed to incorporate accessibility metadata into established schemas - The Geospatial community has specialized geospatial metadata standards - These standards build on traditions of map and image libraries and catalogs - Formal metadata is essential for geospatial data, as common text-processing approaches are not applicable - The Dublin Core metadata terms are vocabulary terms used for resource description - The W3C Data Catalog Vocabulary (DCAT) supplements Dublin Core with classes for Dataset, Data Service, Catalog, and Catalog Record - Microformat is a web-based approach to semantic markup - Metadata can be written into digital photo files to identify ownership, copyright, and contact information