UIPL 18-90 Attachment 2

INSTRUCTIONS FOR CHOOSING SAMPLE

1. Determine the Skip Interval.  Divide the number of cases in the sampling frame of delayed cases (N) by the sample size (n) and round to the nearest integer to obtain. the skip interval (k).

   Examples:

   k = 60 / 30 = 2

   k = 77 / 30 = 2.56, round to 3

   k = 94 / 30 = 3.13, round to 3

2. Determine the Random Start Number.  The table below contains a number for each SESA. Use this to select the random start number for the first case by multiplying the SESA's number by the number of cases in the sampling frame and.rounding to the nearest integer.

   AL	.987		IL	.596		MT	.509		PR	.238
   AK	.576		IN	.758		NE	.630		RI	.226
   AZ	.283		IA	.191		NV	.560		SC	.980
   AR	.682		KS	.350		NH	.101		SD	.997
   CA	.685		KY	.390		NJ	.430		TN	.397
   CO	.954		LA	.924		NM	.551		TX	.507
   CT	.629		ME	.988		NY	.789		UT	.765
   DE	.167		MD	.445		NC	.796		VT	.328
   DC	.042		MA	.316		ND	.570		VA	.981
   FL	.284		MI	.791		OH	.044		WA	.927
   GA	.604		MN	.353		OK	.064		WV	.758
   HI	.178		MS	.651		OR	.086		WI	.465
   ID	.810		MO	.083		PA	.892		WY	.577

3. Identify Remaining Cases.  Select every kth case following the first selection (r), where k is the skip interval, until n (30) cases have been chosen. If the end of the sampling frame is reached before n cases have been selected, return to the beginning of the frame and continue the systematic selection.