Continuous point-of-care patient monitoring is now the standard in emergency room and critical care settings, and the technology to produce small, affordable, safe bedside vital sign monitors is ubiquitous. The statistical methods to validate these emerging monitoring technologies, however, are in their infancy. Validation statistics have centered on the Bland–Altman method and cardiac output measurement, but this method fails to evaluate the ability of a device to reliably detect serial changes (trend analysis). Newer statistical methods such as concordance and polar plots have been developed to assess trending. Small-sized studies assessing within-subject trending require other statistical approaches. Since clinical validation studies must be of a sufficient standard to be used in evidence-based reviews, researchers assessing the value of emerging clinical monitoring technologies must have an understanding of these new statistical methodologies. They must also take into consideration the precision of the reference method and issues pertaining to setting the criteria for accepting a new monitoring method, particularly when using percentage error and the traditional <30% benchmark.