Spreading phenomena are ubiquitous in nature and society. For example, disease and
information spread over underlying social and information networks. It is well known that
there is no threshold for spreading models on scale-free networks; this suggests that spread
can occur on such networks, regardless of how low the contact rate may be. In this paper, I
consider six models with different contact and propagation mechanisms, which include
models studied so far, but are apt to be confused. To compare these six models, I analyze …