In this work, we discuss statistical energy methods for predicting mid-frequency vibration transmission between two spring-coupled substructures with parameter uncertainties. We adopt a parameter-based approach, which allows us to relax certain assumptions associated with a classical Statistical Energy Analysis (SEA) approximation. We consider both a numerical method and an analytical method. The latter is called a Parameter-based Statistical Energy Method (PSEM). An example of two elastic bars coupled by a single spring or multiple springs is examined. The power transmitted from the excited substructure to the other substructure is calculated and compared for the various methods.