Section 532.241 - Analysis of usable wage survey data(a)(1) The lead agency shall compute a weighted average rate for each appropriated fund survey job having at least 10 unweighed matches and for each nonappropriated fund job having at least 5 unweighed matches. The weighted average rates shall be computed using the survey job data collected in accordance with §§ 532.235 and 532.247 and the establishment weight.(2)(i) Incentive and piece-work rates shall be excluded when computing weighted average rates if, after establishment weights have been applied, 90 percent or more of the total usable wage survey data reflect rates paid on a straight-time basis only.(ii) When sufficient incentive and piece-work rate data are obtained, the full incentive rate shall be used in computing the job weighted average rate when it is equal to or less than the average nonincentive rate. If the full incentive rate is greater than the average nonincentive rate, the incentive rate shall be discounted by 15 percent. The discounted incentive rate shall be compared with the guaranteed minimum rate and the average nonincentive rate, and the highest rate shall be used in computing the job weighted average rate.(b) The lead agency shall compute paylines using the weighted average rates computed under paragraph (a) of this section. (1) The lead agency shall compute unit and frequency paylines using the straight-line, least squares regression formula: Y = a + bx, where Y is the hourly rate, x is grade, a is the intercept of the payline with the Y-axis, and b is the slope of the payline. (i) The unit payline shall be computed using a weight of one for each of the usable survey jobs and the weighted average rates identified and computed under paragraph (a) of this section.(ii) The frequency payline shall be computed using a weight equal to the number of weighted matches for each of the usable survey jobs and the weighted average rates identified and computed under paragraph (a) of this section.(2) Either or both of the lines computed according to paragraph (b)(1) of this section may be recomputed after eliminating survey job data that cause distortion in the lines.(3) The lead agency may compute midpoint paylines using the following formula: Y = (au + af)/2 + ((bu + bf)/2)x, where Y is the hourly rate, x is the grade, au is the intercept of the unit payline, af is the intercept of the frequency payline, bu is the slope of the unit payline, and bf is the slope of the frequency payline. A midpoint line may be computed using the paylines based on all of the usable survey job data as described in paragraph (b)(1) of this section, and a second midpoint line may be computed using the paylines based on limited survey job data authorized in paragraph (b)(2) of this section.(4) The lead agency may compute other paylines for the purpose of instituting changes in the scope of the survey.(c) Usable data obtained from a particular establishment may not be modified or deleted in order to reduce the effect of an establishment's rates on survey findings, i.e., data will not be deleted or modified to avoid establishment domination.46 FR 21344, Apr. 10, 1981, as amended at 55 FR 46141, Nov. 1, 1990. Redesignated at 55 FR 46141, Nov. 1, 1990; 58 FR 32273, June 9, 1993; 60 FR 62701, Dec. 7, 1995