Berninghaus et al. (2007) slightly modify the mathematical model of network formation by Bala and Goyal (2000), and show that a periphery-sponsored star network is a strict Nash equilibrium. To examine the validity of this model, they also conduct laboratory experiments, and obtain inconsistent results with the theoretical prediction. In this paper, assuming implicit coordination of players in network formation processes, we give an explanation for the behavior of the experimental subjects from a point of view of the notion of correlated equilibria.