AS 1484.13.1 pdf download.IEEE Standard for Learning Technology— Conceptual Model for Resource Aggregation for Learning, Education, and Training
3. Definitions, acronyms, and abbreviations
3.1 Definitions For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause. 3 aggregation definition document: A document that lists and structures the digital resources of an aggregation. See also: digital resource; resource aggregation. NOTE—Examples: the manifest document in IMS Content Packaging (IMS CP) (IMS Specification [B9]); the mets documents in the Metadata Encoding and Transmission Standard (METS) ([B19], [B20]); the Digital Item Declaration Language (DIDL) document in MPEG-21 Digital Item Declaration (DID) (ISO/IEC 21000-2:2005 [B15]). 4, 5 aggregation format: A documented method of aggregating digital resources into a complex object that can be exchanged among systems. An aggregation format may be defined by a formal specification or standard, but may also be informal. The defining characteristic is that an aggregation format specifies how to combine digital resources into a structured whole, without prescribing the kinds of digital resources, their internal structures, or their intended uses. See also: digital resource. aggregation instance: An instantiation of an aggregation definition document that includes all data necessary to construct a complex object including any references to external data. Multiple aggregation instances, each of which conforms to a different aggregation format, may exist for the same complex object. See also: aggregation definition document; aggregation format. binding: The process that binds a model to a data structure. For example, it can refer to the binding of a conceptual model to the Web Ontology Language (OWL) ontology language. NOTE—See W3C Recommendation [B29].
class: A category of items that share one or more common characteristics. Characteristics can be described informally in a scope note or formally as properties explicitly formulated in logical terms. A class cannot be defined by enumerating its instances because it is generally impossible to know all instances of a class in the world, and the future can bring new instances into being at any time. See also: class instance; open world; scope note. class extension: The set of all real-life instances belonging to a class that fulfill the criteria of the class’s intention. An extension is an open set in the sense that it is generally impossible to know all instances of a class. In an open world, new instances of a class may be created at any time. See also: class; intention; instance; open world. class instance: An instantiation of a class. A class instance has properties that meet the criteria of the intention of the class. The number of instances of a given class declared in an information system is usually less than the total number of instances in the real world. For example, although an individual is an instance of “person,” the individual may not be mentioned in all information systems describing “persons.” See also: class; intention; property. component: Any data attribute or data element as described by the data model of an aggregation format. See also: aggregation format; data attribute; data element.. data attribute: A characteristic of a unit of data, often expressed in Extensible Markup Language (XML). data element: A uniquely named and defined component of the data model of an aggregation format into which data items (actual values) can be placed. See also: aggregation format; component. digital resource: Any resource that can be expressed in an electronic format, such as binary formats, Extensible Markup Language (XML), plain text, various encodings (e.g., base64), media-specific formats, and compressed archives (e.g., zip files).NOTE—Media-specific formats include Joint Photographic Experts Group [JPEG] (ISO/IEC 10918-1) [B13]) and MPEG–1 Audio Layer 3 [MP3] (ISO/IEC 13818-3 [B14]). domain: A constraint on a property that limits the class instances to which the property can be applied. Instances of a property are applicable to instances of its domain. For example, if property A has only the classes X and Y as a domain, then only instances of classes X and Y can have property A. See also: class; class instance; property; property instance; range. identifier: Associates a name with a thing. Context defines how the name is interpreted. Within a given context, a name is unique.