in the fourth and fifth editions of the 16pf, there were five global factors that seem to correspond fairly closely to the "big five personality traits". the big five (bf) trait of openness seems to be related to 16pf openness/tough-mindedness, the bf trait of conscientiousness to the 16pf self-control, the bf extraversion to the 16pf extraversion, the bf agreeableness/dis-agreeableness to the 16pf independence/accommodation, and the bf neuroticism to the 16pf anxiety. in fact, the development of the big-five factors began in 1963 with w.t. norman factor-analyzing responses to the same items as the 16pf, replicating cattell's work and suggested that five factors would be sufficient.