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
All the way through "There's a consistency to physical objects that somehow reads all the way through, so that when you make a physical object, if it lacks the proper amount of weight or if it lacks a certain density...I mean, if its outside says, 'I weigh so much and I have such-and-such a density,' and when you pick it up, you discover an inconsistency there, then you can sense that, you can see it, even without picking it up. It's absolutely essential that everything be done all the way through." Lawrence Wechler & Robert Irwin, Seeing Is Forgetting the Name of the Thing One Sees Invisible substanceA great painting has to be better than it has to beFinished on the insideSigning partyWhy YKK zippers are the brown M&Ms of product designYou'll know it's there objectscraft