This experiment tested how 18-month-old infants' prior experience with an object affects their imitation. Specifically, we asked whether infants would imitate an adult who used her head to illuminate a light-box if they had earlier discovered that the light could be illuminated with their hands. In the Self-Discovery condition, infants had the opportunity to freely explore the lightbox; all infants used their hands to activate the light-box at least once during this period. The experimenter then entered the room and, while providing explicit pedagogical cues, demonstrated illuminating the light-box using her forehead. In the Demonstration Only condition, infants just viewed the experimenter's demonstration. During a subsequent testing phase, infants in the Demonstration Only condition were more likely to use their foreheads to activate the light-box. Conversely, infants in the Self-Discovery condition were more likely to use their hands, suggesting that efficiency can "trump" pedagogy in some observational learning contexts. (Contains 1 table.)