Emotions are brief episodes during which several functional components are synchronized in response to an eliciting event. Emotions can be assessed by measuring responses in each of these components: subjective feeling, physiology, expression, and motivation. In this article we review the most advanced methods that can be used to assess emotions in each of the four components: self-report measures and questionnaires, measures of physiological activation, instruments for the analysis of nonverbal expressive behavior, and behavioral tasks.