Abstract
1. Motivations for and development of this special issue The idea of proposing a special issue on the use of foundational ontologies for modelling simple everyday, or commonsense, situations came after several discussions with people in different domains which pointed to difficulties in understanding the philosophical and general presentations in the documentation accompanying foundational systems. This problem, we noticed, is worsened by the lack of step-by-step guidance to model a real situation from the point of view of a specific ontology. The result was that different knowledge engineers could generate mutually inconsistent models starting from the very same foundational ontology even when working on the same topic. Given that one of the main roles of ontologies is to serve as interoperability drivers, this conclusion was puzzling if not discouraging. We observed that it would not be possible to provide solutions to these issues without involving the very teams that developed foundational ontologies. On the other hand, if we could collect a series of presentations centred around the presentation of modelling cases, we would also have fostered a more consistent use of foundational ontologies, and set the bases for practical and comparative evaluations of the consequences in adopting one ontology rather than another. Another contribution that a special issue on " Foundational Ontologies in Action " could provide, and whose consideration eventually led to the particular selection of use cases discussed in this special issue, is to indicate how these ontologies differ in modelling core aspects in knowledge engineering practices. Such core aspects include the description of artefacts and their components, the modelling of changes