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12.3 Sampling Procedures <br />• Sample adequacy will be tested during field sampling using the formula in DRMS <br />Regulation 4.15.11(2)(a), as follows: <br />t <br />n. _ 6& )2 <br />where: <br />n,,, = minimum sample size <br />S = Sample variance (n -1 degrees of freedom) <br />d = Precision (0.10 for cover and production; 0.15 for woody <br />plant density) <br />x = Sample arithmetic mean <br />t = The (a =.10) t -table value for a 1 tail t -test, n -1 degrees of <br />freedom (infinite degrees of freedom may be used if n> 30) <br />n = Sample size <br />During field sampling for cover and production, at least 15 samples (observational units) <br />will be made at each site. Sample adequacy will be tested after 15 samples are taken, <br />• using a field laptop computer. Sampling may continue if necessary to reach sample <br />adequacy, or sampling may be terminated before sample adequacy is reached if an <br />alternative statistical method (approved by DRMS) can be used that does note require <br />demonstration of sample adequacy. Alternative procedures will require a minimum of 30 <br />samples, as detailed below. Because dry- weight production data will not be available until <br />samples are dried., sample adequacy will initially be calculated on fresh weights of clipped <br />material, then recalculated later for air -dried material and additional field samples will be <br />taken if necessary. <br />Reclaimed area cover and production will be compared to a standard equal to the mean <br />values measured at the reference area by sampling, as described below. Revegetation <br />will be considered "successful" if the mean value for the reclaimed site can be <br />demonstrated to equal or exceed "Q" (Q =90% of the standard). One of the following four <br />methods will be used to compare mean values at reclaimed sites to Q, depending on the <br />mean values and whether sample adequacy was reached during sampling. <br />1) If sample adequacy exists at the reclaimed site and the reference area, and the <br />reclaimed site mean is equal to or greater than Q, no statistical comparison is necessary <br />and revegetation at the reclaimed site will be deemed successful for the parameter in <br />question. This complies with the provisions of DRMS Regulation 4.15.11(2)(a). <br />2) If sample adequacy exists at the reclaimed site and the reference area, and the mean <br />value at the reclaimed site is less than Q, a "standard null" one -sided t -test with alpha <br />error probability of 0.10 will be used, in conformance with DRMS Regulation 4.15.11(2)(b), <br />• using the general form of the one -sided t -test as follows: <br />REVISED 11 Nov 09 Tab 22 -27 <br />