One of the most frustrating aspects of motion sickness is the apparent lack of predictability, particularly from one context (seasickness) to another (cybersickness). It has been postulated that this lack of predictability is indicative of separate but related disorders. Recent evidence has suggested that the problem may not lie in the disorder itself, but in the measures used to predict it. Based on the predictions of Riccio and Stoffregen (1991) and the findings of Smart, Stoffregen, and Bardy (2002), a secondary analysis was performed using parameters of postural motion in order to classify participants who would later become motion sick across three laboratory (four modes of presentation: moving room (Smart, et al, 2002), high fidelity flight simulator (Stoffregen, et al, 2000) large screen projection, and head mounted display (Often, 2005)) settings. Results suggest that measures of postural instability may serve as a common, minimally invasive, and predictive index of visually induced motion sickness.