© 2006 Patrick Durusau and Steven R. Newcomb Information Systems, Tribalism, and Subject Maps Patrick Durusau, Snowfall Software Steve Newcomb, Coolheads Consulting Extreme Markup Languages 2006 Montréal, August 14 Slides and files:

© 2006 Patrick Durusau and Steven R. Newcomb A subject map is a set of subject proxies. A subject proxy is a set of properties. ≡ ≡ {,,,,, } value class value class value class value class value class value class An expression of a subject proxy represents a subject, and that expression is addressable, i.e., it has identity. value class value class value class value class value class value class (subject ) (e.g. oid=4a5f) {,,,,,,,,,, }

© 2006 Patrick Durusau and Steven R. Newcomb value class value class value class value class oid=2 value class value class oid=3 Expressions of different proxies can represent the same subject. value class value class value class value class value class value class (subject ) oid=1

© 2006 Patrick Durusau and Steven R. Newcomb value class value class value class value class oid=2 value class value class oid=3 One or more properties of every proxy identify its subject. value class value class value class value class value class oid=1 class value class (subject ) value class value class value class (subject )

© 2006 Patrick Durusau and Steven R. Newcomb (the Statue of Liberty) In any given subject map, there is no requirement that any subjects have any proxy expressions to represent them… …except for property classes. The class of every property must have at least one proxy expression. (the property’s value) (an expression of a proxy for the property’s class) (the proxy in which the property appears) (the property’s class)

© 2006 Patrick Durusau and Steven R. Newcomb Proxy expressions representing various subjects. A subject map (many properties and proxies not shown). A proxy expression representing a property class. (the property’s value) (the proxy expression representing the property’s class) (the proxy in which the property appears) A property. value

© 2006 Patrick Durusau and Steven R. Newcomb Set of information resources Rules for making proxies. Classes of information resources Subject Map Disclosure of semantics of properties. ≡an expression of a subject map Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. ++ the “legend”

© 2006 Patrick Durusau and Steven R. Newcomb An expression of a subject map is not the same thing as a subject map… Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. ++ the “legend” ≡ …just as an expression of a set is not the same thing as a set… “{1, 2, 3}” ≡ {1, 2, 3}

© 2006 Patrick Durusau and Steven R. Newcomb (subject: the content model of the element type “foo”) …just as different expressions can represent the same subject. <!ELEMENT foo ( bar | baz)* > <xs:choice minOccurs=“0” maxOccurs=“unbounded”>

© 2006 Patrick Durusau and Steven R. Newcomb IRS publications Rules for recognizing subjects in IRS pubs and making proxies for them IRS Publications DTDs IRS Tax Map (in the abstract; not yet rendered) Disclosure of semantics of properties. ++≡an expression of a subject map Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. First example: IRS Tax Map the “legend”

© 2006 Patrick Durusau and Steven R. Newcomb An XTM topic map Rules for recognizing subjects in XTM instances and making proxies for them XTM DTD XTM topic map seen as a subject map. Disclosure of semantics of XTM properties. ++≡an expression of a subject map Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. Second example: An XTM topic map the “legend”

© 2006 Patrick Durusau and Steven R. Newcomb A TMDM instance Rules for recognizing subjects in TMDM instances and making proxies for them TMDM infoset (ISO ) TMDM instance seen as a subject map. Disclosure of semantics of the properties of proxies found in subject map views of TMDM instances. ++≡an expression of a subject map Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. Third example: A TMDM instance the “legend”

© 2006 Patrick Durusau and Steven R. Newcomb A corpus of s. Rules for recognizing subjects in instances and making proxies for them. The structures of the s in the corpus. Corpus of s seen as a subject map. Disclosure of semantics of proxy properties. ++≡an expression of a subject map Some set of information resources Rules for recognizing subjects and making proxies for them. Disclosure of semantics of properties. Last example: A corpus of s the “legend”