1. A computer controlled method comprising: accessing a first coefficient vector that represents a first temporal profile and a second coefficient vector that represents a second temporal profile, said first temporal profile representing a presence history of a first entity within a persistent virtual environment, said second temporal profile representing a presence history of a second entity within said persistent virtual environment; generating a predictive function responsive to said first coefficient vector and said second coefficient vector, said predictive function providing a likelihood with respect to a future time that said first entity and said second entity will be temporally compatible; and presenting a representation of said predictive function or information derived from said predictive function.