INPUT AS RELATED TO OUTPUT 7 
Table 4. — Factors affecting rate of planting seed potatoes, determined by net 
correlatimi analysis 
On the average, for each additional- 
The 
quantity 
of seed 
was in- 
creased — 
Closeness of the 
relation 
Dollar's worth of manure or fertilizer 
Cultivation.. 
Spraying 
Inch depth in plowing 
Bushels 
0.08 
0.13 
0.44 
0.63 
Net coefficients 
r = +0. 191 ±0.038 
r = +0. 117±0.038 
r = +0. 252 ±0.037 
r = +0. 241 ±0.037 
The multiple correlation of all four factors with the quantity of 
seed was i?=0.428±0.032, showing that the quantity of seed used 
was related to the cultural factors to a greater extent than was the 
value of fertilizer applied. Furthermore, the number of sprayings 
and the depth of plowing had the closest relation to the quantity of 
seed used, although the other two factors also had some relation. 
Carrying the analysis through for all the principal factors of 
input would give a very complete statement of how variations in the 
different factors are interrelated. It would show to what extent farm- 
ers varied their applications of fertilizer to fit different soil condi- 
tions, different applications of seed, etc. ; to what extent they changed 
the quantity of seed used as more fertilizer was applied, different 
varieties were planted, more cultivations given, different cultural 
methods used, more sprayings given, or different rotations followed, 
and so on in turn for each factor. With such information properly 
presented, a farmer would be able to compare his practices with those 
of other farmers, not only with the average of all the farmers in the 
region, but with the average practice of those operating on soils of 
the same fertility and using the same cultural methods that he used. 
The accuracy of such comparisons would depend upon the extent to 
which the factors studied were correlated with the practice under 
consideration. 
In this case the multiple correlation of 0.428 ±0.032 for the fac- 
tors related to seed input indicates that there were many other reasons 
for variations in the seed input than the four factors included. The 
more of these additional factors that were measured and included in 
the analysis the closer the multiple correlation would approach 1.00 
and the more valuable would be the results. 
With such detailed data one could say " the practices on this 
farm are the same as those on other farms operated under the same 
conditions," or " differ from the practices on farms operated under 
the same conditions in (such and such a way)." Collection, analysis, 
and presentation of data in such a way as to make possible this kind 
of comparison are the first steps toward making these data fit the 
actual need of individual farmers. 
FEED INPUTS FOR BEEF CATTLE 
A somewhat more complicated case is that of feed fed to beef cattle, 
or dairy cows, or swine. The following analysis shows some of the 
difficulties for beef cattle. Table 5 shows the variations in feed 
fed per day for 67 droves of cattle in Nebraska. Figure 2 presents 
