<prompt> Translate the following text to EnglishNAO inachunguza mbinu za sampuli za DWP na matokeo ya sampuli, inachunguza baadhi ya kesi DWP ilichunguza, na huchagua sampuli yake mwenyewe ili kuthibitisha usahihi wa ukaguzi.  <response>: NAO reviews DWPs sampling methodology and sample results, reviews some of the cases DWP examined, and selects its own sample to verify the accuracy of the reviews. 