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
Finished on the inside "Those stretcher bars were finished on the inside in ways no one will ever know; I spent days, weeks, months finishing things no one is ever going to see. But it had much more to do with the fact that I couldn't leave them unfinished. I just had this conviction that in the sense of tactile awareness, if all those things were consistent, then the sum total would be greater, even though that might not be definable in any causal, connected way." Lawrence Wechler & Robert Irwin, Seeing Is Forgetting the Name of the Thing One Sees All the way throughInvisible substanceCompleting work properly in unseen areas craft