Think aloud: effects and validity

Think aloud is a commonly used usability method with roots in psychology. Although current think aloud practice was adapted from a standard method defined by Ericsson and Simon, there is no evidence of the use of a standard method by usability practitioners. We present the results of a study exploring usability practitioners' awareness of the effects of think aloud and whether validity as defined by Ericsson and Simon is relevant to usability practice. Results indicate that practitioners are aware of some of the effects of think aloud. However, it is not clear whether practitioners are aware of or concerned with the reactive effects of think aloud.