▁help ▁un cover ▁the ▁basic ▁dimensions ▁underlying ▁a ▁confusing ▁array ▁of ▁surface ▁variables ▁within ▁a ▁particular ▁domain . ▁ ▁F actor ▁analysis ▁was ▁built ▁upon ▁the ▁earlier ▁development ▁of ▁the ▁correlation ▁coefficient , ▁which ▁provides ▁a ▁numerical ▁estimate ▁of ▁the ▁degree ▁to ▁which ▁variables ▁are ▁" co - related ". ▁ ▁For ▁example , ▁if ▁" fre quency ▁of ▁exercise " ▁and ▁" blo od ▁pressure ▁level " ▁were ▁measured ▁on ▁a ▁large ▁group ▁of ▁people , ▁then ▁inter cor rel ating ▁these ▁two ▁variables ▁would ▁provide ▁a ▁quant itative ▁estimate ▁of ▁the ▁degree ▁to ▁which ▁" ex erc ise " ▁and ▁" blo od ▁pressure " ▁are ▁directly ▁related ▁to ▁each ▁other . ▁F actor ▁analysis ▁performs ▁complex ▁calculations ▁on ▁the ▁correlation ▁coefficients ▁among ▁the ▁variables ▁within ▁a ▁particular ▁domain ▁( such ▁as ▁cogn itive ▁ability ▁or ▁person ality ▁trait ▁construct s ) ▁to ▁determine ▁the ▁basic , ▁unit ary ▁factors ▁underlying ▁the ▁particular ▁domain . ▁ ▁While ▁working ▁at ▁the ▁University ▁of ▁London ▁with ▁Spe ar man ▁expl oring ▁the ▁number ▁and ▁nature ▁of ▁human ▁ab ilities , ▁C att ell ▁post ulated ▁that ▁factor ▁analysis ▁could ▁be ▁applied ▁to ▁other ▁areas ▁beyond ▁the ▁domain ▁of ▁ab ilities . ▁ ▁In ▁particular , ▁C att ell ▁was ▁interested ▁in ▁expl oring ▁the ▁basic ▁tax onom ic ▁dimensions ▁and ▁structure ▁of ▁human ▁person ality . ▁He ▁believed ▁that ▁if ▁expl or atory ▁factor ▁analysis ▁were ▁applied ▁to ▁a ▁wide ▁range ▁of ▁measures ▁of ▁inter person al ▁function ing , ▁the ▁basic ▁dimensions