The problem with trees Many systems are organized hierarchically. The CERNDOC documentation system is an example, as is the Unix file system, and the VMS/HELP system. A tree has the practical advantage of giving every node a unique name. However, it does not allow the system to model the real world. For example, in a hierarchical HELP system such as VMS/HELP, one often gets to a lead on a tree such as: HELP COMPILER SOURCE_FORMAT PRAGMAS DEFAULTS only to find a reference to another leaf: Please see HELP COMPILER COMMAND OPTIONS DEFAULTS PRAGMAS and it is necessary to leave the system and re-enter it. What was needed was a link from one node to another, because in this case the information was not naturally organized into a tree. Tim Berners-Lee, Seeing With Fresh Eyes A City Is Not a Tree hierarchywww
Cool URIs don't change An Essay by Tim Berners-Lee www.w3.org What makes a cool URI? A cool URI is one which does not change. What sorts of URI change? URIs don't change: people change them. The User Interface of URLs www
The Art of Looking Sideways A Book by Alan Fletcher www.alanfletcherarchive.com Cover art for Alan Fletcher's wonderfully expansive commonplace book. Thinking is drawing in your headThe picket fenceThe chicken was the egg's idea for getting more eggs The brain is wider than the skyWhat this site is graphicsdesigncommunicationcommonplacestylecollections
The picket fence There was a fence with spaces you could look through if you wanted to. An architect who saw this thing stood there one summer evening. Took out the spaces with great care and built a castle in the air. The fence was utterly dumbfounded, each post stood there with nothing round it. Christian Morgenstern www.andrew.cmu.edu spacearchitectureabsurdity