1 , ▁before ▁being ▁promoted ▁to ▁Full ▁Professor ▁with ▁the ▁chair ▁Long itud inal ▁Data ▁Analysis ▁in ▁ 2 0 1 8 . ▁Since ▁ 2 0 1 4 ▁she ▁has ▁also ▁been ▁a ▁research ▁fellow ▁at ▁the ▁Research ▁Group ▁of ▁Quant itative ▁Psych ology ▁and ▁Ind ividual ▁D iffer ences , ▁K U ▁Le u ven , ▁in ▁Belg ium . ▁ ▁Research ▁focus ▁ ▁Ham akers ▁early ▁research ▁focused ▁on ▁the ▁application ▁of ▁time ▁series ▁techniques ▁within ▁psych ology , ▁to ▁study ▁process ▁that ▁unfold ▁within ▁individuals ▁over ▁time . ▁In cre ased ▁avail ability ▁of ▁data ▁collected ▁using ▁the ▁experience ▁sampling ▁method ▁in ▁psych ology ▁led ▁to ▁increased ▁interest ▁in ▁this ▁method ology ▁in ▁applied ▁psych ological ▁research . ▁Most ▁notable ▁of ▁her ▁papers ▁is ▁her ▁critique ▁of ▁the ▁cross - lag ged ▁panel ▁model , ▁in ▁which ▁she ▁propos es ▁to ▁better ▁account ▁for ▁stable ▁trait - like ▁differences ▁between ▁individuals ▁through ▁the ▁use ▁of ▁mult ile vel ▁models ▁with ▁random ▁intercept s . ▁She ▁is ▁also ▁an ▁advoc ate ▁of ▁within - person ▁thinking ▁in ▁social ▁sciences , ▁pointing ▁out ▁that ▁conclus ions ▁based ▁on ▁cross - section al ▁data ▁do ▁not ▁necessarily ▁general ize ▁to ▁the ▁processes ▁within ▁a ▁particular ▁person . ▁▁ ▁Since ▁ 2 0 1 5 ▁Ellen ▁has ▁collabor ated ▁frequently ▁with ▁Beng t ▁O . ▁M uth én ▁and ▁T ih om ir ▁As par ou hov ▁in ▁the ▁development ▁of ▁the ▁Dynamic ▁Struct ural ▁Equ ation ▁Model ing , ▁a ▁module ▁that