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
Togetherness “Togetherness” is a fittingly nauseating name for an old ideal in planning theory. This ideal is that if anything is shared among people, much should be shared. “Togetherness,” apparently a spiritual resource of the new suburbs, works destructively in cities. The requirement that much shall be shared drives city people apart. When an area of a city lacks a sidewalk life, the people of the place must enlarge their private lives if they are to have anything approaching equivalent contact with their neighbors. They must settle for some form of “togetherness,” in which more is shared with one another than in the life of the sidewalks, or else they must settle for lack of contact. Inevitably the outcome is one or the other; it has to be; and either has distressing results. City residential planning that depends, for contact among neighbors, on personal sharing of this sort, and that cultivates it, often does work well socially, if rather narrowly, for self-selected upper-middle-class people. It solves easy problems for an easy kind of population. So far as I have been able to discover, it fails to work, however, even on its own terms, with any other kind of population. Jane Jacobs, The Death and Life of Great American Cities Doing community classcommunity