( ( ( ( ( ( Given ( ( the ( precise definition ) ) ( of ( parsimony ( as ( ( an assumption ) ( about ( the world ) ) ) ) ) ) ) ) ( , ( we ( ( should never ) ( ( insist ( on parsimony ) ) ( as ( ( a ( general principle ) ) ( of ( designing theories ) ) ) ) ) ) ) ) ) , ) but ) ( it ( ( is ( useful ( in ( those situations ) ) ) ) ( where ( we ( have ( ( some knowledge ) ( of ( ( the simplicity ) ( of ( ( the world ) ( we ( are studying ) ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (PP (VBN Given) (NP (NP (DT the) (JJ precise) (NN definition)) (PP (IN of) (NP (NP (NN parsimony)) (PP (IN as) (NP (NP (DT an) (NN assumption)) (PP (IN about) (NP (DT the) (NN world))))))))) (, ,) (NP (PRP we)) (VP (MD should) (ADVP (RB never)) (VP (VB insist) (PP (IN on) (NP (NN parsimony))) (PP (IN as) (NP (NP (DT a) (JJ general) (NN principle)) (PP (IN of) (S (VP (VBG designing) (NP (NNS theories)))))))))) (, ,) (CC but) (S (NP (PRP it)) (VP (VBZ is) (ADJP (JJ useful) (PP (IN in) (NP (DT those) (NNS situations)))) (SBAR (WHADVP (WRB where)) (S (NP (PRP we)) (VP (VBP have) (NP (NP (DT some) (NN knowledge)) (PP (IN of) (NP (NP (DT the) (NN simplicity)) (PP (IN of) (NP (NP (DT the) (NN world)) (SBAR (S (NP (PRP we)) (VP (VBP are) (VP (VBG studying))))))))))))))) (. .)))
Given the precise definition of parsimony as an assumption about the world, we should never insist on parsimony as a general principle of designing theories, but it is useful in those situations where we have some knowledge of the simplicity of the world we are studying.
(ROOT (S (NP (NP (DT The) (NN law)) (PP (IN of) (NP (NN parsimony)))) (VP (VBZ is) (NP (NP (DT the) (JJ scientific) (NN concept)) (VP (VBG stating) (SBAR (IN that) (S (SBAR (WHADVP (WRB when)) (S (VP (VBG looking) (PP (IN at) (NP (CD two))) (NP (VBG competing) (NNS theories))))) (, ,) (NP (NP (DT the) (NN one)) (PP (IN with) (NP (JJR fewer) (NNS assumptions)))) (VP (MD should) (VP (VB be) (VP (VBN chosen))))))))) (. .)))