  In this paper we discuss opinion dynamics in the Opinion Changing Rate (OCR)
model, recently proposed (A.Pluchino, V.Latora and A.Rapisarda Int. J. Mod.
Phys. C, 16, No.4, 515-531 (2005)). The OCR model allows to study whether and
how a group of social agents, with a different intrinsic tendency rate to
change opinion, finds agreement. In particular, we implement the OCR model on a
small graph describing the topology of a real social system. The nodes of the
graph are scientists partecipating to the Tepoztlan conference, celebrating
Alberto Robledo's 60th birthday, and the links are based on coauthorship in
scientific papers. We study how opinions evolve in time according to the
frequency rates of the nodes, to the coupling term, and also to the presence of
group structures.
