  For instance, some social scientists who use agent-based simulation pursue a methodology in which social phenomena (for example an observed pattern like segregation) are explained, or accounted for, by generating similar looking phenomena in their simulations (Epstein and Axtell 1996; Epstein 1999). But this raises its own sorts of epistemological questions. What exactly has been accomplished, what kind of knowledge has been acquired, when an observed social phenomenon is more or less reproduced by an agent-based simulation? Does this count as an explanation of the phenomenon?  A possible explanation? (see e.g., Grüne-Yanoff 2007).  Giuseppe Primiero (2019) argues that there is a whole domain of “artificial sciences” built around agent-based and multi-agent system based simulations, and that it requires its own epistemology--one where validation cannot be defined by comparison with an existing real-world system, but must be defined vis a vis an intended system.