Only some of the variation is significant, by being detectable or perceivable, to speakers. Perceivable, Operable, Understandable and Robust. All these events would happen in milliseconds not perceivable to humans but perceivable to computers. The minimization of perceivable artifacts is a key goal in implementing a lossy compression algorithm. Value refers to the degree of perceivable lightness of tones within an image. This effectively reduces the volume of the perceivable noise. Events that leave behind perceivable physical or virtual remains can be traced back through data. The differences between OPM and UML are highly perceivable during the analysis and design stages. Most perceivable colors can be formed by mixing different amounts of three primary colors. A big ball of mud is a software system that lacks a perceivable architecture. In Belarus there was no perceivable change in status. Time limits were established to avoid long fights on the ground with little perceivable action.