In this thesis, a computer simulation model created in the early 1960s by Robert P. Abelson and Alex Bernstein is examined. The simulation described was built to reflect processes involved in formation of a public opinion within a population taking into account direct communication as well as communication mediated through mass media. After describing and thoroughly analyzing the available description of the simulation model this thesis produces the implementation of a running software simulation system implementing this model. The software is developed and described using common computer science procedures and finally examined for its properties during different tests.