Walker and Avant (2005) define empirical referentsaswaystomeasuretheconceptintherealworld. There is a proliferation of articles describing tools or instruments to measure the perceptions of groups or individuals. Tools have shown to be successful in some attempts, but fail in others. In health care, quality indicators have been developed to capture the patient’s perceptions regarding the hospital experience, especially about the quality of nursing care they received. Dozier et al. (2001)