▁life ▁behav iors , ▁meas uring ▁their ▁characteristic ▁behavior ▁patterns ▁in ▁the ▁real ▁world . ▁ ▁This ▁could ▁range ▁from ▁number ▁of ▁traffic ▁acc idents ▁or ▁number ▁of ▁parties ▁attended ▁each ▁month , ▁to ▁grade ▁point ▁average ▁in ▁school ▁or ▁number ▁of ▁ill ness es ▁or ▁divor ces . ▁ ▁Ex perimental ▁data ▁( or ▁T - data ) ▁which ▁involves ▁re actions ▁to ▁standard ized ▁experimental ▁situations ▁created ▁in ▁a ▁lab ▁where ▁a ▁subject ' s ▁behavior ▁can ▁be ▁object ively ▁observed ▁and ▁measured . ▁ ▁Question naire ▁data ▁( or ▁Q - data ), ▁which ▁involves ▁responses ▁based ▁on ▁intros pection ▁by ▁the ▁individual ▁about ▁their ▁own ▁behavior ▁and ▁feelings . ▁ ▁He ▁found ▁that ▁this ▁kind ▁of ▁direct ▁question ing ▁often ▁measured ▁subt le ▁internal ▁states ▁and ▁view points ▁that ▁might ▁be ▁hard ▁to ▁see ▁or ▁measure ▁in ▁external ▁behavior . ▁ ▁In ▁order ▁for ▁a ▁person ality ▁dimension ▁to ▁be ▁called ▁" fund amental ▁and ▁unit ary ," ▁C att ell ▁believed ▁that ▁it ▁needed ▁to ▁be ▁found ▁in ▁factor ▁anal ys es ▁of ▁data ▁from ▁all ▁three ▁of ▁these ▁measurement ▁domains . ▁Thus , ▁C att ell ▁constructed ▁measures ▁of ▁a ▁wide ▁range ▁of ▁person ality ▁tra its ▁in ▁each ▁medium ▁( L - data ; ▁Q - data ; ▁T - data ). ▁ ▁He ▁then ▁conducted ▁a ▁program m atic ▁series ▁of ▁factor ▁anal ys es ▁on ▁the ▁data ▁derived ▁from ▁each ▁of ▁the ▁three ▁measurement ▁media ▁in ▁order ▁to ▁el uc id ate ▁the ▁dimensional