The recall score is the percentage of TV viewers who can recall within 24 hours the brand of the ad they were exposed to during the normal course of viewing TV. These scores are then indexed against the mean score for all new ads during the time period (recall index). 100 equals average.
In addition to an overall ranking, the Quarterly report also features the most-recalled ads in the following product categories: automotive, wireless, restaurant, consumer products and prescription drugs.
The overall ad performance ranking also includes an additional measure of likability, which is derived from an ad's likability score and likability index. The likability score is the percentage of viewers who claim to like an ad "a lot" (among those who can recall the ad and its associated brand). These scores are then indexed against the mean score for all new ads during the time period (likability index). 100 equals average.
For same-length spots with minor variations, all versions are aggregated to yield one combined score. All ads under consideration must meet a minimum survey sample size of 200. The Overall Top 20 Recall ranking is based on over 1.8 million surveys of TV viewers conducted between Jan 2 and Apr 1. Total sample size varies across individual product category rankings.