1.1 This test method covers the assessment of changes of surface appearance of pile floor coverings after exposure to actual or simulated foot traffic. This test method applies to pile yarn floor coverings that are, or have been, installed, laboratory floor-trafficked samples, or textiles floor coverings trafficked by mechanical traffic simulators. The subjective assessment is facilitated by use of reference scales that are based on digital images of representative pile yarn floor covering styles and constructions.