- From: Thompson, Bryan B. <BRYAN.B.THOMPSON@saic.com>
- Date: Tue, 10 Aug 2004 15:37:51 -0400
- To: "Roy T. Fielding" <fielding@gbiv.com>, www-tag@w3.org
Roy, Is this meant to describe a situation in which a complex "resource" is revealed through a set of URIs, all of which encode some state that lets the server disambiguate which view of the resource to send to the client. For example, the entire telephone directory is available, perhaps as RDF/XML, from: http://www.mytelco.com/phonebook However using one mechanism or another, the server is willing to send a representation of all phonebook information for a person, business, zip code, city, state, etc. E.g., http://www.mytelco.com/phonebook/people/Your%20Name http://www.mytelco.com/phonebook/biz/Your%20Biz%20Name http://www.mytelco.com/phonebook/zip/20009 http://www.mytelco.com/phonebook/state/CA So, these URIs all "alias" the parts of the state (a phone book) on the server. Is this something that the text, below, is meant to be critical of? What I think is happening is that it is difficult to talk about the referent of the URI and therefore it is difficult to talk about URI aliases. If two URIs reveal precisely the same state, then fine. However I would consider the examples above partially aliased state in the sense that using PUT to update a person's information, /people/foo, would cause updates to be reflected in the entire phone book, in the view for the zip code in which they live, etc. Thanks, -bryan -----Original Message----- From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] On Behalf Of Roy T. Fielding Sent: Tuesday, August 10, 2004 3:06 PM To: www-tag@w3.org Subject: URI aliases: suggested text for webarch 2.3.1 [URI aliases, 2.3.1] URI aliases are harmful when they cause bifurcation in the web of related resources. A corollary of Metcalfe's Principle (the "Network Effect") is that the value of a given resource can be measured by the number and value of other resources that link to it (the network neighborhood of the measured resource). This type of valuation is commonly used to rank the relative value of search results (e.g., Google) because people tend to create links relating a given topic to those resources that they feel best reflect that topic, and hence the number of inbound references are a reflection of the degree to which the community values a resource. The problem with aliases is that if half of the neighborhood points to one URI for a given resource, and the other half points to a second, different URI for that same resource, the neighborhood graph splits (bifurcates). The aliased resource is not the only one undervalued because of this split: the entire neighborhood of resources become undervalued due to the missing second-order relationships that should have existed among the referring resources by virtue of their references to the aliased resource. [note, aliases are also in 2.2 for some reason unknown] ....Roy
Received on Tuesday, 10 August 2004 19:38:05 UTC