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Statistical Methods <br />Statistical Design <br />Cover data sampling proceeded using a single stage statistical design. <br />Sample locations in reclaimed areas were randomly plotted by use of an internal script <br />routine within ArcView 9.3 software. Minimum spacing between sample points was 170 <br />feet (one 50 m. transect length). The SCC-assigned number of samples for a given <br />parameter in a given area reflect previously experienced sample variability or the level <br />of precision required for that area. In 1998, Sample locations were randomly plotted by <br />hand. <br />Sample points were located in the field using Garmin 60 GPS handheld units and <br />topographic maps. Cover transects were oriented using, at a glance, the seconds <br />reading on a wristwatch x 6 or a blind spin of a meter stick as a azimuth. At each cover <br />sampling location, the slope (percent) and aspect of the site were determined and <br />recorded, as was the orientation of the transect (in degrees not corrected for magnetic <br />declination). <br />Confidence Limits <br />Confidence limits for comparison to reference areas and technical standards were <br />calculated using a 1-tailed t-value for alpha error probability of 0.10 at (n-1) degrees of <br />freedom multiplied by the standard error of the mean of the sampled area. <br />C.I. = t s <br />t <br />Ö <br /> n <br />Performance Standards for Use in Interim Monitoring Assessment <br />Cover: For purposes of comparison only, data collected in 1998 for the <br />Sagebrush/Rabbitbrush vegetation type at the Hayden Gulch Loadout were used as a <br />4 <br />