60 Nebraska Agricultural Exp. Station, Research Bui. 13 
The three foregomg tables (27-29) show the exact ar- 
rangement in which the 207 Kherson oats plats were grown 
in the field. Certain plats have been designated as check 
plats according to each of the above three methods, and the 
intervening plats have been treated as test plats. The test 
plats have been corrected in yield according to the check 
plats. If such correction had been effective, the coefficient 
of variability for the corrected yields would have been ma- 
terially reduced below the coefficient of variability for the 
actual yields. On the contrary, however, the coefficients of 
variability were reduced less than 1 per cent, being 7.8 per 
cent for the actual yields and 7.0 per cent for the corrected 
yields, as an average for the three methods of correction. 
Table 30 gives the coefficients of variability for the actual 
and corrected yields of the test plats indicated in Tables 27, 
28, and 29. 
Table 30 — Effect upon yield from correcting thirtieth-acre 
Kherson oats field plats according to various accepted 
means of check plat correction"^ (1916) 
Arrangement of 
check plats used 
for correction 
Fre- 
quency 
Intervening 
plat yields 
Standard devia- 
tion from 
mean for 
Coefficient of 
variability for 
Actual 
yields 
Cor- 
rected 
yields 
Actual 
yields 
Cor- 
rected 
yields 
Actual 
yields 
Cor- 
rected 
yields 
Alternate check 
plats. Correc- 
tion based upon 
average of two 
adjacent checks 
102 
Bushels 
78.2 
Bushels 
78.1 
Bushels 
6.14 
Bushels 
5.47 
Per cent 
7.85 
Per cent 
7.01 
Checks every third 
plat. Correc- 
tion based upon 
one adjacent 
check plat . ... 
138 
78.0 
77.7 
6.08 
5.71 
7.79 
7.35 
Checks every third 
plat. Correc- 
tion by progres- 
s i V e method 
based upon two 
nearest checks . . 
132 
78.0 
77.7 
6.13 
5.10 
7.87 
6.57 
-Calculated from data in Tables 27, 28, and 29. 
