Full bibliography

Scientific theory evolves through phases. Scientists observe phenomena, classify their observations, examine and explain causation, and attempt to understand their results in varied circumstances. If anomalies are found that do not mesh with the theory, revision occurs, and the theory is improved (Christensen, Carlile, & Sundahl, 2001). Each stage requires accurate and precise measurement and, therefore, appropriate measurement tools.The body of scientific inquiry developed by A. Jean Ayres is deeply rooted in systematic and methodical measurement, and her work marked the first effort by an occupational therapist to build a theory for clinical application with an evidence-based approach. The trajectory of the growth of Ayres Sensory Integration® (ASI), beginning in the 1950s with continual advancements from the ongoing contributions of the researchers who have built on her seminal work since that time, has occurred simultaneously with the widespread use of more rigorous research methods, attention to measurement of fidelity, greater usage of exploratory and factor analysis, and more routine practice of examining multivariate research problems with computer statistical programs (Century, Rudnick, & Freeman, 2010; Elmore & Woehlke, 1988; Keselman et al., 1998; Ottenbacher & Peterson, 1985; Press, 2013; Tukey, 1980; West, Carmody, & Stallings, 1983).