Abstract: Since the small world network is one of the most common complex networks in the real world, this paper focuses on information diffusion on the small world network platform. In order to explore the relationship between structural features of the small world network with a well-accepted feature for information diffusion, network coverage ratio named, the methodology of multi-agent based modeling and simulation is introduced, instead of mathematical modeling. Through simulation, the impact of only two parameters in the small world network generation algorithm, that is Watts-Strogatz algorithm, is analyzed, where the process of information diffusion acts as the SIR model. The simulation results get not only the bimodal pattern of distribution of the network coverage, but also its relationship with characteristics of the network generation algorithm. The regression function of network coverage ratio variable with the complex network characteristics such as average path length, network diameter, and average clustering coefficient is built.

Key words: SIR model, information diffusion, network coverage index, small world network, multi-agent modeling and simulation