Discussions have recently taken place on whether spatiotemporal information is more important than featural information when infants attempt to individuate objects. Hitherto, spatiotemporal and featural information have only been compared directly by using cognitively demanding ‘event-mapping designs’ (e.g. Xu & Carey, 1996), whereas the simpler event-monitoring designs (e.g. the ‘wide-screen/narrow-screen’ by Wilcox and colleagues) have not been employed for such a comparison. The present research offers a new event-monitoring design, the rotating screen design, that allows for such a direct comparison. Three experiments in which 9.5-, 8.0-, and 6.5-month-old infants attempt to individuate objects by spatiotemporal and featural information are reported. The results showed that whereas the 9.5-month-old infants were able to individuate objects by spatiotemporal as well as featural information, the infants of the younger age groups only successfully individuated objects when provided with spatiotemporal information, but not with featural information.