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Glossary of Terms for Metadata, Taxonomies
and Digital Libraries

Maintenance of this glossary ceased in 2010.


 
A glossary is a set of defined terms. Each term has a single definition. The definition is relative to the domain, in this case metadata, taxonomies and digital libraries. Some terms may have multiple definitions according to a standard dictionary. A glossary will use one of these definitions or will create a separate definition.
Look at some of the Dr. Tom’s Guides to see some of these terms in use.

| A-C | D-E | F-J | K-Q | R-S | T-V | W-Z |


ADL
Advanced Distributed Learning Initiative. Manages the development of SCORM and the CORDRA system.
Aggregate
To collect or gather together. 
Assessment
"Any systematic method of obtaining evidence from tests, examinations, questionnaires, surveys and collateral sources used to draw inferences about characteristics of people, objects, or programs for a specific purpose." from the Testing and Assessment Glossary of Terms of QuestionMark: http://www.questionmark.com/us/glossary.htm. (Contributed by Eric Shepherd).
AICC
Aviation Industry CBT Committee The Aviation Industry CBT (Computer-Based Training) Committee (AICC) is an international association of technology-based training professionals. The AICC develops guidelines for aviation industry in the development, delivery, and evaluation of CBT and related training technologies.
Architecture
The organizational structure of a computer system, including hardware and software. [from http://www.epa.gov/records/gloss/gloss02.htm.]
Authority List
A controlled list of terms, names, phrases or similar entries relative to a specific domain or scope. An authority list may or may not contain definitions or other information about each item. A glossary or dictionary contain definitions. Typically an authority list provides the standard spelling and form of terms. Authority lists have defined managers, e.g., the British Library's Name Authority List (http://www.bl.uk/services/bibliographic/authority.html). Authority Lists may have structure, such as the hierarchy of the Library of Congress' Subject Headings: http://www.loc.gov/cds/lcsh.html
Blog
A Weblog of short, frequently updated entries, some of which allow responses.
Blogisphere
The complete clade of blogs.
Category
A selection, subset or subdivision of a classification. See also Dr. Tom’s Classification Guide 
Catalog
"A database which contains descriptions of information resources and their locations," Pipher, Hayes & Davis (1998).
CEN/ISSS/LTWS
European Committee for Standardization [Comité Européen de Normalisation]: Information Society Standardization System: Learning Technology Workshop
Change Management
Change management is a planned process for changing a core function or organization of an enterprise. Interestingly, the process of developing a taxonomy can result in the need for change. See Quality Assurance.
Clade
A clade is a group of the same species that includes all ancestors. Adopted from the biological term.
Classification
"1 : the act or process of classifying
2 a : systematic arrangement in groups or categories according to established criteria; specifically : TAXONOMY b : CLASS, CATEGORY "* Classification is both the systematic arrangement of labels and the application of those labels. Dr. Tom’s Classification Guide 
COE
Common Operating Environment: http://diicoe.disa.mil/coe/index.html. See also Robin Cover's U.S. Federal CIO Council XML Working Group Issues XML Developer's Guide: http://xml.coverpages.org/ni2002-01-16-a.html.
Collection
A collection is an aggregation of resources. It may—or may not—all be packaged in one resource or content package. It has no inherent navigational structure. It may have an index and/or table of contents. Items may be accessed on an individual basis. An example is a collection of images. A collection may be housed in a library or repository. Most collections have a theme.
Community
A group with one or more common interests. The European SchoolNet has many learning communities supported by tools.
Community of Practice (CoP)
A community or group with a common interest. CoPs frequently use the internet to facilitate their activities. This facilitation may include forums, libraries, chat rooms, calendars and such. See the Community of Practice list http://groups.yahoo.com/group/com-prac/.
Concept
2 : an abstract or generic idea generalized from particular instances * See Note on Subjects and Concepts.
Computational Linguistics
Attemtps to use computers to process natural human language.
Content
A specific kind of resource that is packaged into a usable state. A document is content.
Content Package
An assemblage of content items and possible support files or headers. Support files may include a manifest and/or sequencing files or sections.
CORDRA
CORDRA is a project of the Advanced Distributed Learning (ADL) initiative. The Content Object Repository Discovery and Registration/Resolution Architecture (CORDRA) is designed to be an enabling model to bridge the worlds of learning content management and delivery, and content repositories and digital libraries. CORDRA will use the Handle System.
Crosswalk
Mapping of a term or concept between metadata formats. See also Thesaurus. The UKOLN has provided a list of many crosswalks, although this is not exhaustive. CanCore provides a Dublin Core to LOM crosswalk.
 

Data Set
An organized collection of data.
Data Base
A software structure that contains one or more data sets. A data base that holds one data set may make the two seem to be one and the same. A data base is an application or tool, it is not its contents. Question: do we consider the technical metadata to refer to the data set or the data base?
Data Model
A description of the structure of data elements.
Dictionary
An organized collection of definitions and uses of terms. A term may have more than one definition and more than one use. Contrast with glossary, thesaurus, taxonomy and index
Digital Library
"[N]etworked information in the research and education communities." "[Digital] Libraries... [are] ...technological and social developments that are fueled by information technology, bioinformatics, and networked information." http://www.cni.org/, http://www.diglib.org/dlfhomepage.htm. DLESE is an example of a digital library within the NSF's NSDL.  
Directory
"[An] alphabetical or classified list (as of names and addresses)".* A directory is simple and flat, usually providing a set of name - location pairs. See also Index.
DTD
Document Type Definition for describing an XML structure: http://xml.coverpages.org/XMLSpecDTD.html. XML-Schemas allow richer descriptions at the price of complexity.  
Dublin Core (DC)
The Dublin Core Metadata: http://dublincore.org/. A core set of 15 elements or fields that are used to describe resources. It is a widely used basic system of metadata good for wide area searching. Often expressed as HTML metatags. Sometimes "qualifiers" are added to refine the definitions of each field. When in doubt, DC is a good starting place for metadata, as it is widely used. DC is implemented with a variety of technical formats. DC is compatible with Z39.50, as DC defines descriptive labels and Z39.50 describes technical formats and transmission protocols.
Element
A component in a metadata structure. Each element has a token
Extension
To go beyond the original form. For instance for XML see Dr. Tom’s Guide to IMS XML Extensions and Incorporations 
 

Facet
A fundamental category by which an object or concept may be described. For example, a child’s ball may be described using the facets of size, weight, shape, color, texture, material and price. (http://www.boxesandarrows.com/view/all_about_facets_controlled_vocabularies)
FEDORA
The FedoraTM Project An Open-Source Digital Repository Management System.
Field
A bin or hole in a metadata structure into which appropriate values are placed. This is not to be confused with an element. The simplest metadata field is a metatag
Glossary
A list of terms with single definitions with respect to a particular domain. "[A] collection of ... specialized terms with their meanings".* Contrast with dictionary, thesaurus and authority list
Granularity
Level of graininess or size. 
Handle System
"The Handle System is a comprehensive system for assigning, managing, and resolving persistent identifiers, known as ‘handles,’ for digital objects and other resources on the Internet. Handles can be used as Uniform Resource Names (URNs)". A handle is a unique identifier (UID) within a defined scope. The Handles System for the US Department of Defense (DOD) will be used by DTIC (http://www.dtic.mil/dtic/handles/) for the DOD's management of learning objects. This will interface with ADL's CORDRA system. 
The IEEE LTSC
Institute of Electrical and Electronic Engineers' Learning Technology Standards Committee : http://ltsc.ieee.org
Index
A pointer to a resource of some type or a list of such pointers. Typically an index is an alphabetical list of words and phrases. The terms in the index have no definitions assigned to them as opposed to a taxonomy in which terms may have meanings. A taxonomy does not point to specific references. See also Directory.  
IMS Global Learning Consortium
"IMS Global Learning Consortium, Inc. (IMS) [is a non-profit corporation that] is developing and promoting open specifications for facilitating online distributed learning activities such as locating and using educational content, tracking learner progress, reporting learner performance, and exchanging student records between administrative systems. " These are busy people. http://www.imsglobal.org
Intelligent Tutoring
Intelligent tutoring systems attempt to duplicate the one-on-one teaching process using artificial intelligence. Online IT systems accomplish this in a distance education setting.
ISO9000
A standard for quality assurance. http://www.iso.org/iso/en/iso9000-14000/index.html
ISO 11179 (JTC1 SC32)
Standard for describing data elements used in databases and documents: http://metadata-standards.org/11179/. Sponsoring body: ISO/IEC JTC1/SC32. As an example implementation see the Australian Institute of Health and Welfare Data Standards: http://www.aihw.gov.au/dataonline.cfm
Item
A unit or resource of arbitrary size. 
 

Knowledge Management (KM)
An organizational process for converting information into knowledge and making that knowledge accessible. It is more a state of mind and a commitment than a specific set of tools. Tools are used, however. See Brint: http://www.brint.com/km/. KM and online learning are merging in some enterprises.
Learning Object
The term "learning object" has a variety of definitions. I prefer a broad definition: a package of one or more resources that have educational utility. I am not going to try to specify "educational utility"; that is in the eye of the beholder, so to speak. Sometimes the definition states that the object must be specific for learning. Sometimes there is a requirement for an assessment component. The variety of definitions makes use of the term "learning object" unreliable without reference to a specific definition.
LETSI
The International Federation for Learning, Education, and Training Systems Interoperability. "LETSI supports the long-term sustainability of eLearning initiatives by promoting and facilitating standards innovation and harmonization." "LETSI is a non-profit association of individuals and organizations who see the need for a sea change in the way technology is used in education and job training."
Localization
Adapting to a praticular language, culture or region. For example, an enterprise may "localize" its taxonomies through a thesaurus or crosswalk.
LOM
The Learning Object Metadata standard of the IEEE LTSC. The IEEE LTSC working group is #12: http://ltsc.ieee.org/wg12/index.html.
LTSO
Learning Technology Standard Observatory: http://www.cen-ltso.net. Not a standard, but a place to go to see international standards of interest related to online education and training. Also has other useful information and calendar of events related to online learning.
Manifest
A packing slip for a content package. A manifest in a content package may contain or point to metadata, define the resources contained in the content package and define an intended organization of the resources.
Memetics
The study of evolution in information systems, c.f. Journal of Memetics - Evolutionary Models of Information Transmission, http://pespmc1.vub.ac.be/MEMES.html
Metadata (bibliographic)
Information that catalogs or describes a resource. This may include metadata defining the resource subject, format, location, ownership, authorship and so forth. Some may validly consider metadata a resource. See also Dr. Tom’s Metadata Guide, Wason, T., and Wiley, D. (2001). "Structured Metadata Spaces".
Metatag
A named field. Typically metatags are not structured, but are used as a simple name-value pair datum. Metatags a normally associated with HTML as <meta> elements in the header. See for example the Meta Tag Tutorial at WebDeveloper.com. Some web search engines use the metatags, some do not. 
MIME
Multipurpose Internet Mail Extensions. Generally accepted designations of file format types. MIME is an example of a recommended standard that has not yet been approved but is widely used. This is an example of how the world works at "Web speed.". If you wait for the formal standard before proceeding, you may be left at the back of the pack. On the other hand, if you select a recommendation that is either not approved or undergoes significant change before approval, you may have a lot of expensive revision to do. Enterprises participate in standards groups to try to discern the future.
NSDL
The National Science Foundation's National Science Digital Library Initiative: NSF NSDL.
OAI 
Open Archives Initiative: http://www.openarchives.org/ The OAI has developed a metadata harvesting protocol, OAI-PMH. This is used in the NSDL and elsewhere. 
OAI-PMH
Open Architecture Initiative Protocol for Metadata Harvesting: http://www.openarchives.org/OAI/openarchivesprotocol.html, http://www.openarchives.org/ (OAI).
OASIS 
"OASIS (Organization for the Advancement of Structured Information Standards) is a not-for-profit, international consortium that drives the development, convergence, and adoption of e-business standards. The consortium produces more Web services standards than any other organization along with standards for security, e-business, and standardization efforts in the public sector and for application-specific markets."
OKI 
Open Knowledge Initiative: http://web.mit.edu/oki/ 
Ontology
1 : a branch of metaphysics concerned with the nature and relations of being * See Note on Subjects and Concepts and Facet. An ontology is a concept map, e.g., source > power > electrical. An ontology is a representation of the relatioships among concepts. See also taxonomy, which is an organized set of terminology.
Perceptual Coupling
Matching the nature or structure of information to the precognitive processing of the human perceptual system to promote the rapid recognition or meaning of information. Perceptual coupling has a variety of applications generally involving situation management.
Qualifier
Refines or limits the definition of a metatag. DC provides qualifiers. 
Quality Assurance
Quality assurance (QA) is process for ensuring that an enterprise’s products or services are provided according to well-defined standards, specifications or methods. The most highly regarded and formal standard for a qualtiy control process is ISO 9000 and its relatives. The development of metadata and taxonomies can often result in changes in an enterprise's business processes. QA can be effective as a component of change management. See Change Management.
 

RDF 
Resource Description Framework of the W3C: http://www.w3.org/RDF/. Uses XML for a self-describing data structure system. 
Registry
Information that defines what is stored in one or more repositories. It may contain specialized vocabularies and taxonomies. A registry may contain metadata describing other registries, repositories or objects within repositories. A "registered" repository may have to adhere to certain rules in order to be registered. The difference between "registry" and "repository" is not consistent in use.
Repository
A storage site for resources, which may include metadata. A repository may house a collection. Contrast with a registry or a collection.
Resource
Any asset that can be bounded in some manner. It may be a data stream, but its parameters are well defined. Content, data sets and data streams are resources. A tool may be considered a resource. A source of supply or support.* Stuff.
SAML
Security and Authentication Markup Language: http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=security Defining and maintaining a standard, XML-based framework for creating and exchanging security information between online partners
SCORM 
Sharable Content Object Reference Model http://www.adlnet.org/ 
Semantics
The study of meanings: a : the historical and psychological study and the classification of changes in the signification of words or forms viewed as factors in linguistic development.* 
Semantic Web
The gleam in Tim Berners-Lee's eye for a unified Web without metadata: http://www.w3.org/2001/sw/ 
SMET
An acronym for Science, Mathematics, Engineering and Technology, sometimes with "
Education" included at the end.
Specification
"a detailed precise presentation of something or of a plan or proposal for something -- usually used in plural".* A specification is created by an enterprise, as opposed to a standard, which is maintained by an official body. For example the IMS Global Learning Consortium and Intel develop specifications. Examples are the IMS Meta-Data Specification and the Intel Audio Codec Specifications
SOA
There are two definitions of "service oriented architecture" (SOA) in circulation. Some refer to SOA as a system of enterprise services for business integration, others as a Web based architecture of services with standard interfaces that supports services that are independently developed to interoperate. Know which is being discussed. CORDRA is the latter.
SRW
Search/Retrieve Web service: http://xml.coverpages.org/ni2004-03-04-a.html. SRW is "an XML-based protocol designed to be a low-barrier-to-entry solution for searching and other information retrieval operations across the Internet."
Standard
"[S]omething set up and established by authority as a rule for the measure of quantity, weight, extent, value, or quality ".* IEEE and ISO develop standards. An example is the IEEE LTSC Learning Object Metadata standard (under ballot). Recommended, but not yet approved, standards such as MIME are widely used. Not yet approved standards may be designated RFC (Request for Comments).  
Subject
3 a : a department of knowledge or learning * See Note on Subjects and Concepts.
 

Tag
See Metatag
Tautology
A self referential definition or system of logic. See tautology.
Taxonomy
A taxonomy is a terminology map of a topic or discipline. It is a structured vocabulary that embodies relationships among terms. Each term is contained in a taxon. Denise A. D. Bedford, Ph.D. of the world bank enumerates four types of taxonomies: flat, hierarchical, faceted and network (Taxonomies for Information & Knowledge Management Architectures, URL: http://www.sla.org/chapter/cdc/presentations/20030204_taxonomies.ppt). The most common relationship is a hierarchy (tree structure), e.g., electronics > power supply. Other forms may include cross linking and poly-hierarchical structure. A vocabulary is a single level taxonomy. See also Dr. Tom’s Taxonomy Guide. Some major taxonomies are: MARC, LCSH, MeSH. For a long list of many taxonomies in many domains see: Controlled vocabularies, thesauri and classification systems available in the WWW. DC Subject (http://www.lub.lu.se/metadata/subject-help.html) Originally referred to biological classifications: "[O]rderly classification of plants and animals according to their presumed natural relationships".* Compare with thesaurus. See also ontology.A taxonomy has or infers a glossary. A glossary has only one definition per term as opposed to a dictionary that may have more than one definition per term, e.g., fast. The glossary may be an authority list. An ontology, on the other hand, is an organization of concepts. It may govern the application of terms in a taxonomy.
Taxon
A node in a taxonomy. A taxon may contain a term, and reference label and links to other taxons.
Thesaurus
A collection of terms, their definitions (that may be multiple) and relationships to other terms. Contrast with taxonomy, dictionary and glossary. " [A] list of subject headings or descriptors usually with a cross-reference system for use in the organization of a collection of documents for reference and retrieval".* 
Token
An element's name or set of characters that are the logical equivalent of a name. 
UDDI
Universal Description Discovery & Integration (http://uddi.org/pubs/uddi-v3.0.2-20041019.htm) of OASIS. "...the definition of a set of services supporting the description and discovery of (1) businesses, organizations, and other Web services providers, (2) the Web services they make available, and (3) the technical interfaces which may be used to access those services. Based on a common set of industry standards, including HTTP, XML, XML Schema, and SOAP, UDDI provides an interoperable, foundational infrastructure for a Web services-based software environment for both publicly available services and services only exposed internally within an organization. "
UID
Unique Object Identifier. A UID provides a token designating a specific object. Each UID has only one occurrence within its defined scope of use. Uniqueness may be specified by a statistical probability of recurrence or through an assignment system, such as the Handle System, that enforces uniqueness through policy. A globally unique identifier theoretically has no duplication within the known set of all UIDs. 
Vocabulary
A list of terms, sometimes with definitions. A single level taxonomy. A vocabulary can be considered a very localized glossary. Or not. 
 

WSDL
Web Services Description Language, http://www.w3.org/TR/wsdl.
XML
eXtensible Markup Language of the World Wide Web Consortium: http://www.w3.org/TR/REC-xml. A method for serializing structured data for use on the Internet. This is not yet an official standard, but is in a "recommended" state. See also http://www.xml.org.
XML-Schema
A control system for XML: http://www.w3.org/XML/Schema. This is not yet an official standard, but is in a "recommended" state. See Dr. Tom’s Guide to XML-Schema , IMS XML bindings, DTDs and Examples.http://www.imsglobal.org/xsd/.
XSL
The Extensible Stylesheet Language for creating different views of XML documents: http://www.w3.org/Style/XSL/
XSLT
The Extensible Stylesheet Language for Translating XML documents to different formats: http://www.w3.org/Style/XSL/. This is part of the XSL specification. 
Z39.50
  " A technical data format and transmission protocol specification. "Z39.50" refers to the International Standard, ISO 23950: ’Information Retrieval (Z39.50): Application Service Definition and Protocol Specification‘, and to ANSI/NISO Z39.50. The Library of Congress is the Maintenance Agency and Registration Authority for both standards, which are technically identical (though with minor editorial differences).
  "The standard specifies a client/server-based protocol for searching and retrieving information from remote databases. " http://www.loc.gov/z3950/agency/ 


Last edit: 2010/08/01

A glossary is forever a work in progress.

Note that I have not attempted definitions of mode, genre or theme. I welcome clear, commonly accepted differential definitions of these—and any other—terms. Comments on the above definitions are welcome, too.  


This glossary has been prepared by Thomas D. Wason. Some definitions are taken from the Merriam-Webster Online Dictionary at http://www.m-w.com/dictionary.htm. If multiple definitions are available, the most appropriate one is selected. Entries from the Merriam-Webster Online Dictionary are designated with an asterisk (*).

Copyright © 2000 - 2010 Thomas D. Wason
 
   

             tdwason@ncsu.edu
             http://www.tomwason.com
             Raleigh, NC USA

Copyright © 2017 Thomas D. Wason