 (CA2)  introduced a different sense of modelling for CA, i.e., the idea that CA are fruitfully used in current scientific practices to study an incredible variety of phenomena: chemical systems (e.g., Kier, Seybold, &amp; Cheng 2005), urban growth (e.g., Aburas et al. 2016), traffic flow (e.g., Lárragaa et al. 2005), even warfare (e.g., Ilachinski 2004). According to the characterization of Barberousse, Franceschelli, and Imbert 2007  (Other Internet Resources),  a common technique is the “phenomenological” modelling. Phenomenological modelling happens when one models in a direct way, that is, without making use of a previous explanatory theory: one looks at how traffic flows and tries to build a CA that reproduces a sufficiently similar behaviour and allows to make useful predictions. The key question for modellers here is, 