Intentional binding refers to a temporal attraction in the perceived times of actions and effects. So far, it has solely been investigated using judgments of the perceived time of actions or their effects. The authors report 3 experiments using an alternative method: the estimation of a time interval between a voluntary action and its subsequent effect. Interval estimates were obtained for intervals bounded by different kinds of actions and effects: The actions were either performed by the participants themselves or by the experimenter. The effects, in turn, were movements either applied to the body of the participant or to the experimenter. First, the results validated interval estimation as a method for exploring action awareness. Second, intentional binding was stronger for self-generated compared with observed actions, indicating that private information about the action contributes to action awareness. In contrast, intentional binding did not depend on whether a somatic effect was applied to the participant's or to another person's body. Third, for self-generated actions, external events gave rise to a stronger intentional binding than did somatic effects. This finding indicates that intentional binding especially links actions with their consequences in the external world.