(Color online) Degree evolution 〈ρ_O(t)〉 of two divided object groups (a,b) and the ratio ϕ of rewarded objects in two divided object groups with different parameter q (c,d) for two empirical data sets, in which the time t is measured in days, and the parameter θ is set to 0.3 and 0.6 for the MovieLens and Netflix data sets, respectively.

From the subplots (a,b) one can find that the average degrees of objects rated by high perceptibility users in the future time window are larger than those of the other objects. From the subplots (c,d) one can find that the ratio ϕ of rewarded objects in objects rated by high perceptibility users is higher than that in the other objects with different parameter q. The results indicate that the user perceptibility is helpful to find the potential rewarded objects.