Before revision:  In the context of the experimental sciences, well-controlled perturbations can be applied to a system, probing the internal structure of the network .
After revision:  In the context of the experimental sciences, well-controlled perturbation experiments are widely used to probe the structure of complex networks. However, our understanding of how and why perturbations aid inference remains heuristic, and we lack automated procedures that determine network structure by combining inference and perturbation .