Difference (from revision 6 to 7)

Changed: 3c3

'''In general''' an ontology specifies of a vocabulary of concepts predicates together with some indication of their meanings. There is a range of levels of precision with which meaning is specified, but an overall goal is that people often want to share a common understanding of the structure of information among people or software agents. Often there are twin targets to make the meaning clear to people while allowing a degree of "automated" processing. In this case an ontology is used to make explicit the semantics and knowledge contained within efforts such as software applications. {nid 2JOA}
'''In general''' an ontology specifies of a vocabulary of concepts predicates together with some indication of their meanings. There is a range of levels of precision with which meaning is specified, but an overall goal is that people often want to share a common understanding of the structure of information among people or software agents. Often there are twin targets to make the meaning clear to people while allowing a degree of "automated" processing. In this case an ontology is used to make explicit the semantics and knowledge contained within efforts such as software applications. {nid 2JOA}

Changed: 9c9

A class is a concept in the domain so we may have a class of organizations (e.g. USGS) or a class of regions (e.g. Mid-Atlantic States). A class also has a population. It is a collection of the elements with similar properties defined by the class concept. Thus there are instances of states in the Mid-Atlantic class. {nid 2JOC}
A class is a concept in the domain so we may have a class of organizations (e.g. USGS) or a class of regions (e.g. Mid-Atlantic States). A class also has a population. It is a collection of the elements with similar properties defined by the class concept. Thus there are instances of states in the Mid-Atlantic class. {nid 2JOC}

Added: 15a16,20


An informal example of a very small ontology is show below illustrating a 3 relations (part, sub-type and instance) of a portion of the USGS hydrology model for "hydrologic units". The ontological model has 4 sub-types showing a range of aggregation. Thus regions or sub-regions are a type of hydrologic unit and a specific instance of a region is the Mid-Atlantic, which includes as part of it Delaware. For accounting purposes Delaware may be dividing into parts - in this case and upper and lower part. These are asserted as both part of Delaware and as an instance of an "accounting Unit"
http://ontolog.cim3.net/file/work/SOCoP/Pictures/example%20of%20an%20ontology.png {nid 2JOD}

A final sub-type of hydrologic unit is a "cataloguing unit" which has even finer part of accounting units and in this case the Skullkill is an instance of this and part of the Lower Delaware accounting unit. {nid 2JOE}