▁adm itting ▁expert ▁testim ony ▁dedu ced ▁from ▁a ▁well - recogn ized ▁scientific ▁principle ▁or ▁discovery , ▁the ▁thing ▁from ▁which ▁the ▁dedu ction ▁is ▁made ▁must ▁be ▁sufficiently ▁established ▁to ▁have ▁gained ▁general ▁accept ance ▁in ▁the ▁particular ▁field ▁in ▁which ▁it ▁belongs .” ▁ ▁Through ▁this ▁r uling , ▁the ▁judge ' s ▁opinion ▁on ▁F ry e ▁v . ▁United ▁States ▁set ▁preced ent ▁and ▁the ▁standard ▁by ▁which ▁expert ▁witness es ▁would ▁be ▁util ized ▁in ▁the ▁court ▁system ▁for ▁years ▁to ▁come . ▁In ▁the ▁federal ▁courts , ▁between ▁ 1 9 4 8 ▁and ▁ 1 9 7 5 , ▁F ry e ▁was ▁c ited ▁ 5 5 ▁times ; ▁however , ▁the ▁use ▁and ▁application ▁was ▁not ▁consistent . ▁One ▁of ▁the ▁major ▁strugg les ▁that ▁came ▁out ▁of ▁this ▁preced ent ▁was ▁the ▁application ▁to ▁both ▁civil ▁and ▁criminal ▁cases . ▁Many ▁of ▁the ▁courts ▁and ▁jud ges ▁had ▁trouble ▁interpre ting ▁the ▁" general ▁accept ance " ▁notion ▁of ▁a ▁particular ▁field ▁in ▁a ▁conc ise ▁and ▁non - ar bitr ary ▁manner . ▁ ▁Da ub ert ▁standard ▁ ▁The ▁Da ub ert ▁standard ▁arose ▁out ▁of ▁the ▁Supreme ▁Court ▁of ▁the ▁United ▁States ▁case ▁Da ub ert ▁v . ▁Mer rell ▁Dow ▁Ph arma ce ut ical s , ▁Inc .. ▁It ▁requires ▁four ▁things ▁to ▁be ▁shown : ▁▁ ▁That ▁the ▁theory ▁is ▁test able ▁( has ▁it ▁been ▁tested ?) ▁ ▁That ▁the ▁theory ▁has ▁been ▁peer ▁review