Perceived quality is judged as deviation from an ideal amount.

Evidence

A defect can therefore indicate that there is too much or too little of a perceived dimension; listeners responded according to what seemed to them to be appropriate. The responses were solicited for two broad categories, “naturalness” and “pleasantness”, one relating to realism and accuracy, and the other to general satisfaction or preference, without regard to realism. — Toole, Floyd E, Sound reproduction- the acoustics and…, 714

Categorization

• DEFINE: Defines the defect-based perceptual evaluation framework Klippel used.