( ( ( The method ) ( of ( unit conversion ) ) ) ( ( is ( called ( either ( the ( unit ( factor ( method ( or ( dimensional analysis ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN method)) (PP (IN of) (NP (NN unit) (NN conversion)))) (VP (VBZ is) (VP (VBN called) (PP (CC either) (NP (DT the) (NN unit) (NN factor) (NN method) (CC or) (NN dimensional) (NN analysis))))) (. .)))
The method of unit conversion is called either the unit factor method or dimensional analysis.
(ROOT (S (NP (JJ Dimensional) (NN analysis)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB carry) (PRT (RP out)) (NP (JJ metric) (NN unit) (NNS conversions))))))) (. .)))