Frequency domain methods, which are for the design and tuning of control systems for processes with uncertain parameters, and are easy to use and interpret are proposed. The advantages of the proposed methods over other H-infinity methods are mainly that they require substantially less expertise on the part of the designer and that they result in control system performance that closely approximates that which was desired Several examples illustrate the proposed methods. A stable second-order lag and dead time process, with gain and dead rime uncertainties, provides the vehicle for studying controller designs for single and two degree of freedom control systems. Application of MP tuning to art uncertain, unstable, first-order lag, plus dean time process, shows that were can be a significant performance penalty associated with rising a simple feedback control system rather than an internally stable model-based control system. The performance of a controller for an integrating, oscillatory process obtained by Mp synthesis also compares favorably with hat of a controller obtained by other investigators using loop shaping.