ements ▁to ▁expl or atory ▁factor ▁analyt ic ▁method ology ). ▁In ▁his ▁person ality ▁research , ▁he ▁is ▁best ▁remembered ▁for ▁his ▁factor - anal yt ically ▁derived ▁ 1 6 - factor ▁model ▁of ▁normal ▁person ality ▁structure , ▁arg uing ▁for ▁this ▁model ▁over ▁E ys en ck ' s ▁simpler ▁higher - order ▁ 3 - factor ▁model , ▁and ▁construct ing ▁measures ▁of ▁these ▁primary ▁factors ▁in ▁the ▁form ▁of ▁the ▁ 1 6 PF ▁Question naire ▁( and ▁its ▁down ward ▁extensions : ▁H SP Q , ▁and ▁CP Q , ▁respectively ). ▁He ▁was ▁the ▁first ▁to ▁propose ▁a ▁hier arch ical , ▁multi - level ▁model ▁of ▁person ality ▁with ▁the ▁many ▁basic ▁primary ▁factors ▁at ▁the ▁first ▁level ▁and ▁the ▁fewer , ▁bro ader , ▁" second - order " ▁factors ▁at ▁a ▁higher ▁str atum ▁of ▁person ality ▁organization . ▁These ▁" global ▁trait " ▁construct s ▁are ▁the ▁prec urs ors ▁of ▁the ▁currently ▁popular ▁Big ▁Five ▁( FF M ) ▁model ▁of ▁person ality . ▁C att ell ' s ▁research ▁led ▁to ▁further ▁adv ances , ▁such ▁as ▁distingu ishing ▁between ▁state ▁and ▁trait ▁measures ▁( e . g ., ▁state - tra it ▁anx iety ), ▁r anging ▁on ▁a ▁continu um ▁from ▁immediate ▁trans itory ▁emot ional ▁states , ▁through ▁longer - act ing ▁m ood ▁states , ▁dynamic ▁motiv ational ▁tra its , ▁and ▁also ▁relatively ▁end uring ▁person ality ▁tra its . ▁C att ell ▁also