Section 1003.1580 - Statistical sampling(a) In meeting the burden of proof in § 1005.15 of this chapter, the OIG may introduce the results of a statistical sampling study as evidence of the number and amount of claims, specified claims, and/or requests for payment, as described in this part, that were presented, or caused to be presented, by the respondent. Such a statistical sampling study, if based upon an appropriate sampling and computed by valid statistical methods, shall constitute prima facie evidence of the number and amount of claims, specified claims, or requests for payment, as described in this part.(b) Once the OIG has made a prima facie case, as described in paragraph (a) of this section, the burden of production shall shift to the respondent to produce evidence reasonably calculated to rebut the findings of the statistical sampling study. The OIG will then be given the opportunity to rebut this evidence. 81 FR 88364 , Dec. 7, 2016, as amended at 88 FR 42841 , July 3, 2023 81 FR 88364 , 1/6/2017; 88 FR 42841 , 8/2/2023