The emotion type contains different attributes to describe an emotion. An emotion have (or not) a sequence of sampling A complex emotion describes an emotion which is complex in the sense that is composed of several complex emotion descriptions. Still, it refers to a single "entity" (reference or start/end time). Only the tag "complex-emotion" element should have a ref or start/end attributes, to reflect the fact that they are joined single entity. Typical cases are the co-occurrence of two or more emotion, possibly varying in intensity; attempts, where on emotion may be masked by the simulation of another one; or anotation of different modalities.