PREDICTING EGG PRODUCTION IN WHITE LEGHORNS 



277 



The average errors with regard to sign are generally low, that for predic 

 tion from November and from January production gives on the average 

 2.4 eggs too many for the year. For December, February, March and 

 August the prediction is in error by less than 2 eggs. The values predicted 

 irom April, May, June, July, September and October records are about 

 1 to 7 eggs in error. 



TABLE 3 



Average deviation without regard to sign of predicted annual egg record from actual record. Pre 

 diction of annual production from one- and from two-months performance. Equations based on 

 Starrs experience, 1911 to 1917. Test of equations on 415 White Leghorns, Starrs, 1917-1918. 



The average deviations without regard to sign are of course much larger 

 since they constitute a measure of the error of prediction of the records 

 of individual birds. They range from 24.8 to 30.1 eggs. The significance 

 pf errors of this magnitude will be more clearly brought out later. 



The square root of mean square deviation also shows considerable 

 regularity from month to month. These measures are naturally consider 

 ably larger than the average deviation without regard to sign. They 

 range from 32.9 to 38.8 eggs. 



JENETICS 6: My 1921 



