The facilitating motivational effect of feedback on performance has been attributed by some to difficult goals set in response to feedback. In the present article the effect was attributed to the presence of both a difficult goal and feedback about performance in relation to that goal. Eighty families were asked to set a total to reduce their residential electricity consumption for several weeks during the summer, half of them by 20% (a difficult goal) and half by 2% (an easy goal). Within each of these groups, half of the families were given feedback three times a week about their consumption. Twenty more families served as a control. As predicted, the 20%-feedback group conserved the most (13.0%-15.1%) and was the only one that consumed significantly less electricity than the control. It was concluded that improved performance was a result of the joint effect of feedback and goal setting. The implications of the present research for a national residential conservation strategy are discussed.