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
Drawing as a means of thinking Two-dimensional plans or sections can be seen with sketches and more diagrammatic marks all on the same piece of paper in what appears a confusing jumble.’ These sound like Gordon’s ‘wonder plots’. The architects also use their drawings as a means of thinking ‘aloud’, or ‘talking to themselves’, as Gordon put it. For example, Lawson reports the architect Richard MacCormac as saying, ‘I use drawing as a process of criticism and discovery’; and the engineer-architect Santiago Calatrava as saying, ‘To start with you see the thing in your mind and it doesn’t exist on paper and then you start making simple sketches and organizing things and then you start doing layer after layer.... it is very much a dialogue.’ The common elements in these similar descriptions are the use of drawing not only as a means of externalising cognitive images but also of actively ‘thinking by drawing’, and of responding, layer after layer and view after view, to the design as it emerges in the drawings. These observations also confirm Schön’s observation of designing as a ‘reflective conversation’ between the designer and the emerging design. It is the reliance on drawing, and the preference for the immediacy of the interaction and feedback that manual drawing gives, that makes the architects, like Gordon Murray, unenthusiastic about CAD as a conceptual design tool. Nigel Cross & Anita Clayburn Cross, Winning by Design: The Methods of Gordon Murray Section-perspective drawingThe situation talks backWhen we make a model and realize it's rubbish drawing