As an example, take “Waterloo Bridge” as a concept. The first thing we ask is “does it have spatial and temporal extent ?”. It has spatial extent; it spans the River Thames. However, when we examine the temporal extent we realise there have been two bridges at that site. The first, built in 1817 (two years after the battle of Waterloo) was demolished in 1920. The bridge that stands there now was built in 1942. This analysis has immediately highlighted a problem with a name-based approach – there are two bridges of that name, which one are we referring to ? At this point, the analyst can add one or both of the bridges to the ontology, then apply the appropriate names to each. The process also works for types of things. Take “bridges” as a concept. It doesn’t have spatiotemporal extent, so we go to the next question “does it have members ?”. It does – the members are all the bridges in the world. We then identify some exemplar members – e.g. Waterloo Bridge. At this stage, it is advisable to identify exemplars that are “on the edge” of the set – e.g. things that may or may not be bridges – e.g. pontoons, bridging vehicles, etc. so as to accurately identify the extent of the type. The final concept covered by the process is the tuple. A tuple is a relationship between things. If the concept under analysis is neither a type nor an individual, then it must be a tuple. We identify the things at the end of the tuple then add it to the ontology.