▁a ▁mark ▁indicating ▁this ▁fact ) ▁or ▁go ▁on ▁forever . ▁A ▁notion ▁of ▁success ▁spec ifies ▁how ▁the ▁method ▁should ▁conver ge ▁to ▁a ▁correct ▁output ▁in ▁each ▁possible ▁world . ▁A ▁method ▁solves ▁the ▁problem ▁( in ▁a ▁given ▁sense ) ▁just ▁in ▁case ▁the ▁method ▁succeed s ▁( in ▁the ▁appropriate ▁sense ) ▁in ▁each ▁of ▁the ▁possible ▁world s ▁specified ▁by ▁the ▁problem . ▁We ▁say ▁that ▁such ▁a ▁method ▁is ▁reliable ▁since ▁it ▁succeed s ▁over ▁all ▁the ▁ep ist em ically ▁possible ▁world s . ▁Of ▁two ▁non - sol utions , ▁one ▁is ▁as ▁reliable ▁as ▁the ▁other ▁just ▁in ▁case ▁it ▁succeed s ▁in ▁all ▁the ▁world s ▁the ▁other ▁one ▁succeed s ▁in . ▁That ' s ▁all ▁there ▁is ▁to ▁it ! ▁( K elly ▁et ▁al . ▁ 1 9 9 7 ) ▁ ▁On ▁the ▁proper ▁role ▁of ▁method ology : ▁" It ▁is ▁for ▁empir ical ▁science ▁to ▁investigate ▁the ▁details ▁of ▁the ▁mechan isms ▁where by ▁we ▁track , ▁and ▁for ▁method olog ists ▁to ▁dev ise ▁and ▁ref ine ▁even ▁better ▁( in fer ential ) ▁mechan isms ▁and ▁methods " ▁( N oz ick , ▁ 1 9 8 1 ) ▁ ▁See ▁also ▁Algorithm ic ▁learning ▁theory ▁Bay esian ▁confirm ation ▁theory ▁Bel ief ▁revision ▁Comput ational ▁learning ▁theory ▁Ep ist em ology ▁F ormal ▁ep ist em ology ▁Ind uct ive ▁reasoning ▁Language ▁identification ▁in ▁the ▁limit ▁Machine ▁learning ▁Method ology ▁Philosoph y ▁of ▁science