Substantial disagreement exists regarding the definition of EI, with respect to both terminology and operationalizations. One attempt toward a definition was made by Salovey and Mayer (1990) who defined EI as “the ability to monitor one's own and others' feelings and emotions, to discriminate among them and to use this information to guide one's thinking and actions.”
Despite this early definition, there has been confusion regarding the exact meaning of this construct. The definitions are so varied, and the field is growing so rapidly, that researchers are constantly amending even their own definitions of the construct.
At the present time, there are three main models of EI:
Ability EI models
Mixed models of EI
Trait EI model