▁to ▁judge ▁the ▁optimal ▁number ▁of ▁factors ▁to ▁extract . ▁He ▁also ▁developed ▁a ▁new ▁factor ▁analysis ▁rotation ▁procedure — the ▁" Pro cr ust es " ▁or ▁non - orth ogonal ▁rotation , ▁designed ▁to ▁let ▁the ▁data ▁itself ▁determine ▁the ▁best ▁location ▁of ▁factors , ▁rather ▁than ▁requiring ▁orthogonal ▁factors . ▁Add itional ▁contributions ▁include ▁the ▁Co efficient ▁of ▁Profile ▁Similar ity ▁( t aking ▁account ▁of ▁shape , ▁scatter , ▁and ▁level ▁of ▁two ▁score ▁profiles ); ▁P - te chni que ▁factor ▁analysis ▁based ▁on ▁repeated ▁measurements ▁of ▁a ▁single ▁individual ▁( sam pling ▁of ▁variables , ▁rather ▁than ▁sampling ▁of ▁persons ); ▁d R - te chni que ▁factor ▁analysis ▁for ▁el uc id ating ▁change ▁dimensions ▁( including ▁trans itory ▁emot ional ▁states , ▁and ▁longer - last ing ▁m ood ▁states ); ▁the ▁Tax on ome ▁program ▁for ▁as certain ing ▁the ▁number ▁and ▁contents ▁of ▁clusters ▁in ▁a ▁data ▁set ; ▁the ▁Rot op lot ▁program ▁for ▁att aining ▁maximum ▁simple ▁structure ▁factor ▁pattern ▁solutions . ▁As ▁well , ▁he ▁put ▁forward ▁the ▁Dynamic ▁Calcul us ▁for ▁assess ing ▁interests ▁and ▁motiv ation , ▁the ▁Basic ▁Data ▁Rel ations ▁Box ▁( ass ess ing ▁dimensions ▁of ▁experimental ▁designs ), ▁the ▁group ▁s ynt ality ▁construct ▁(" person ality " ▁of ▁a ▁group ), ▁the ▁tri adic ▁theory ▁of ▁cogn itive ▁ab ilities , ▁the ▁Ab ility ▁Dim ension ▁Analysis ▁Chart ▁( AD AC ), ▁and ▁Multiple ▁Abstract ▁Var iance ▁Analysis ▁( MA VA ), ▁with