"Tom Wetmore" <ttw4@verizon.net> wrote in message news:39fb07d6-d331-4eba-aa79-7f550607e60d@googlegroups.com... > Tony, > > Thanks. The proof will be in the pudding! > > I would like to work on the multi-hierarchy place authority, but > I have major projects that take priority right now. > > How would you handle the differences between the geographical > and political distinctions? For example the Greenland example > I gave on the other thread. Or another case, the islands of > St. Pierre and Miquelon that are off the coast of Newfoundland. > > Geographically Greenland and St. Pierre and Miquelon are in > North America. Politically Greenland is "an autonomous > country within the Kingdom of Denmark" while > St. Pierre and Miquelon is an "overseas > collectivity of France". What should a place authority do in a > cases like this? > > I believe that there should be both a geographical hierarchy > and a political one. But from there I don't know exactly > where to go. > > Tom They're good examples Tom. When I started my research, I naively expected to have a purely geographic hierarchy. That quickly evaporated though.My hierarchies start at countries and blatantly ignore continents since there's no agreement on their definition, and not everything belongs to a continent. Hence, the top of my hierarchy is political, becoming administrative within the national boundaries (country, district, etc), and ending with purely geographical for towns, villages, etc., down to households. However, "country" is not really an adequate term. The UK, for instance, is a 'sovereign state' rather than a country, and hasn't existed as long as say 'England'. Northern Ireland is part of the UK (despite the Olympic "TeamGB" name) and is sort of a country but is better described as a dependent territory. On our side of the water we also have 'Crown Dependencies', 'British Overseas Territories', and possibly even the 'British Commonwealth' to consider, but then we're known to be eccentric. The ISO 3166 standard talks of "countries and dependent territories" for the very reasons you point out. However, we need to consider historical entities as well as modern ones which is why ISO 3166-1, ISO 3166-2, and NUTS are inadequate by themselves. My research defines a controlled vocabulary for representing entities in a place hierarchy, and tries to include as many as I personally know of around the world. The beauty of time-dependent hierarchies is that a territory that moves from one entity to another can be represented without having to adopt the modern applicable hierarchy, and without having to displace any parent entity. All entities exist in the database, even if they no longer exist in the real world, or their boundaries have moved, or they have alternate names. Two problems I'm still looking at: (a) how to link two independent places that just happen to occupy the same physical location. For instance, a demolished house or bulldozed road that have been replaced by entirely new entities. (b) an entity that has been split into two or more new entities. This could be a whole country, or even just a farmstead. The two problems are obviously related to some degree. Tony Proctor