Tested whether Ss' incorrect beliefs about motion, which were apparent in pencil-and-paper abstract problems, were actually held in real situations. Several findings in the literature suggest that abstract or unrealistic tasks may fail to tap knowledge and reasoning abilities that are routinely used in more concrete or realistic situations. Three experiments examined this possibility in the context of a specific naive belief, the curvilinear impetus belief. In Exp I, 90 undergraduates were presented with the ball-and-string problem under 3 conditions: no motion, rotation, and trajectories. In Exp II, 72 Ss viewed the spiral tube problem under 6 trajectories. In Exp III, 50 Ss threw a puck through a curved tube. Contrary to expectations, results suggest that the curvilinear impetus belief is used not only on pencil-and-paper problems but also in situations where people observe and interact with moving objects.(18 ref)(PsycINFO Database Record (c) 2016 APA, all rights reserved)