Reliable and valid evaluation of translation quality is one of the fundamental thrusts in present-day applied translation studies. In this chapter, a thumbnail sketch is provided of the developments, in and outside of translation studies, that have contributed to the ubiquity of quality in translation discourse. This sketch reveals that we will probably never stand poised to reliably and validly measure the quality of translation in all its complexity and its ramifications. Therefore, the authors have only sought to address the issue of product quality evaluation. After an introduction of evaluation methods, the authors present the preselected items evaluation method (PIE method) as a perturbative testing technique developed to evaluate the quality of the target text (TT). This presentation is flanked by a case study that has been carried out at the University of Antwerp, KU Leuven, and Zuyd University of Applied Sciences. The case study shows that, on account of its perturbative qualities, PIE allows for more reliable and more valid measurement of product quality.