We assume that the simulation's predicted value of A, ⟨A⟩, can be computed as the expectation ⟨A⟩ = ∑ x p(x; θ 0 )A(x). We estimate this expectation by sampling {x i : i = 1, . . . , N } from the canonical ensemble and computing ⟨A⟩ ≈ 1 N ∑ N i=1 A(x i ), under the assumption that each x i is an independent sample from the canonical ensemble and has the same weight of