What aspect of expression did the Facial Action Coding System (FACS) provide as a key contribution?

Answer

A neutral, objective language to describe facial movement.

FACS functions as a detailed anatomical map describing facial movements via Action Units (AUs), providing a standardized, objective metric necessary for transforming subjective observation into quantifiable data.

What aspect of expression did the Facial Action Coding System (FACS) provide as a key contribution?
inventiontechnologyrecognitionpsychologyemotion