Prywatne prawdy, publiczne kłamstwa: Wskazówki z agentowego modelu dynamiki opinii [Private truths, public lies: Hints from an agent-based model of opinion dynamics] Michał Jarema (Department of Operations Research and Business Intelligence, PWr) This work focuses on agent-based modeling of opinion dynamics. We take into account the fact that internal opinions of agents, i.e., their beliefs, may differ significantly from those expressed publicly. We present a new general model and analyze some of its special cases using Monte Carlo simulations. The aim of this paper is twofold. Firstly, we want to check what are the implications of considering agents' opinions at two levels (private, public) on opinion dynamics. Secondly, we want to present hints from statistical physics that may be useful for socio-economic simulations in general.