Rattan [1], [2] suggests two methods for designing a digital control system to match the performance of a given continuous control system as closely as possible. In this note, two main points am made. First, there are a number of errors in the paper by Rattan [2] that significantly affect its conclusions. Second, neither of the methods is guaranteed to produce a stable closed-loop system, even ff the original closed-loop system is stable. In fact, the two methods will generally lead to unstable dosed-loop systems when the number of free parameters in the compensator design process is large.