Comscore's TV engagement rating, also known as the Stickiness Index, ranks primetime ad-supported cable and broadcast telecasts by the level of viewer engagement, which is determined by comparing the average percentage viewed of each telecast to that of all primetime telecasts with the same duration. Telecasts with the most engaged viewers have a higher Stickiness Index, indicating that more of the audience is tuned inor engagedfor the duration of the telecast