1.1 This guide describes criteria and tests for selecting, evaluating, and training human visual-sensory observers for tasks involving the perception and scaling of properties and phenomena relating to appearance.

1.2 Examples of tests requiring the use of trained observers include but are not limited to those described in the following ASTM standards: on color, Test Method D1535 and Practice E1360; on color difference, Practice D1729 and Test Method D2616; on gloss, Test Method D4449; on metamerism, Practice D4086; and on setting tolerances, Practice D3134.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.