Observe data collection at the moment of measurement See, observe, learn how data are collected at moment and place of measurement. "You never learn more about a process than when you directly observe how data are actually measured," said Cuthbert Daniel, a superb applied statistician. See with fresh eyes. Walk around what you want to learn about. Talk to those who do measurements. See how numbers came to be. Do those measuring know the desired answer? Are those measuring skilled, alert, honest, biased, incompetent, sloppy, tired and emotional?...Artifacts and errors in measurements measured? How are outliers adjudicated? Edward Tufte, Seeing With Fresh Eyes uxmeasurement
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