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term-subject-address-def

Type(s): Issue

Subject Identifiers (1)

Internal Occurrences (5)

  • Description
    • At what level of interpretation does the topic represent the resource? Does it represent that storage location? The stream of bytes? The stream of bytes interpreted in some particular way? The standard must either leave the details open or clarify this. Note that it may be impossible to clarify when the interpretation of locators is left undefined.
  • Opinion
    • I dont think we define it. If for no other reason than we dont have to define what equality is other than the locator. If i had to take the other extreme position i would take the one similar to library science that distinguish between the concept of a work and the individual work. In tm I would adopt a position that this is a stream of bytes from a location. i.e. it is the individual work. - Scope: Graham Moore
    • Re "Does it represent that storage location" the answer must be no. What if the address is reassigned to different hardware containing a copy of the referenced resource? What if the address is notational, as in the above example? What if there are multiple copies of a particular resource (whether notational or not, as per retrieval from caches rather than the original resource)? This must be left an open issue for applications to determine. - Scope: Martin Bryan
    • The way in which a subject address relates to a subject is in many ways related to the means of dereferencing the address. For example, a single http: protocol URI can be dereferenced to many different byte sequences - so the subject address cannot be considered to represent the content at that location. Equally, a urn:isbn: reference cannot be dereferenced at all and could be considered meaningless as a subject address, whereas a unique object identifier in a content management system may actually always return precisely the same sequence of bytes and so could be considered to represent a specific binary object. It might be useful for the SAM to say something about the stability requirements of a subject address - e.g. to represent a specific binary object, a subject address must be given in a notation which cannot be interpreted in such a way as to retrieve two different byte-sequences (excepting error conditions such as network or server outages). - Scope: Kal Ahmed
  • Resolution
    • No precise definition should be given. The subject is the information resource, but what that means is not elaborated on.

External Occurrences (1)

 
Object id: 551
Item identifier(s):
[file:/apps/ontopia.net/tomcat/ontopia-5.3.0/topicmaps/tm-standards.xtm#term-subject-address-def]