 An entirely different analysis of the problem of substantiating a measurement uncertainty relation was offered by Busch, Lahti, and Werner (2013). These authors consider a measurement device \(\cal M\) that makes a joint unsharp measurement of both position and momentum. To describe such joint unsharp measurements, they employ the extended modern formalism that characterizes obervables not by self-adjoint operators but by positive-operator-valued measures (POVM’s). In the present case, this means that the measurement procedure is characterized by a collection of positive operators, \(M(p,q)\), where the pair \(p,q\) represent the outcome variables of the measurement, with 