Before revision: "What is an emotion?", an old riddle is repeatedly being attempted with advance modern tools and understanding of the age. With the new advancements old theories are tested and new ones are formed. Such is the case with theorizing and modeling emotion which is broadly shifting from classical definite marker theory to statistically context situated conceptual theory.
After revision: The focus of the efforts for defining and modelling emotion is broadly shifting from classical definite marker theory to statistically context situated conceptual theory.