High Quality Content by WIKIPEDIA articles! The Naglieri Nonverbal Ability Test (NNAT) is a nonverbal measure of general ability. There are three versions of this test. First is the Naglieri Nonverbal Ability Test - Individual Form published in 2004. Two versions were published in 2007 and 2008, respectively. This includes the group administered Naglieri Nonverbal Ability Test - Second Edition and the Naglieri Nonverbal Ability Test - Online version. Like all nonverbal ability tests, the NNAT is intended to assess cognitive ability independently of linguistic and cultural background.