During the 1970s, Ekman developed a method called the Facial Action Coding System (FACS) to measure all visually discernible facial movement.
Ekman developed FACS to measure facial movement.  
mnli hypothesis: Ekman developed FACS to measure facial movement.   premise: During the 1970s, Ekman developed a method called the Facial Action Coding System (FACS) to measure all visually discernible facial movement.