Researchers have developed two kinds of models of emotional intelligence (EI): The four-factor ability model, which operationalizes EI as four mental abilities, and mixed models of EI, which also include personality traits and effective leadership behaviors. The Mayer, Salovey, and Caruso Emotional Intelligence Test (MSCEIT, Mayer, Salovey, & Caruso, 2002) is the only performance test measuring the four-factor ability model. The scores, however, do not predict work-related criteria after controlling for general intelligence and the five-factor model (FFM) of personality. One may also question the validity of the scores and the evidence for the underlying theory of EI. Mixed models of EI seem to measure well-established psychological constructs (e.g., narrow personality traits) which may explain why the scores predict performance after controlling for general intelligence and FFM. In order to know whether EI is important in the workplace, one must first develop adequate measures of this intelligence, and then demonstrate that it is different from, and more important than, personality traits and general intelligence.