A CRITIQUE OF THE BODY-SURFACE LAW. 



179 



The results of predicting the heat-production of the 136 individual 

 men and of the 103 individual women by these four methods are shown 

 in table 69. Here the deviations of the calculated heat-production in 

 calories per day are shown in units of 75 calories per day range as indi- 

 cated in the first column. The frequencies of deviations of given grade 

 are shown for the four different methods of calculation and for the 

 two sexes in the following eight columns. This table brings out various 

 facts which are not shown by the other methods of comparison hitherto 

 employed. 



1. The deviations of the predicted from the actually observed 

 heat-productions may be very great. Differences of 188 calories and 

 over, either above or below the observed values, occur in many cases. 



TABLE 69. Comparison of amounts and frequencies of error by different methods of 

 prediction based on all men and women. 



2. The distribution of the errors of estimation is not chaotic, but 

 remarkably regular in all cases. The errors form monomodal more 

 or less symmetrical distributions, i.e., they are distributed around 

 a maximum control frequency. 



3. The errors of estimation in the case of prediction from average 

 heat-production per kilogram of body-weight are obviously far greater 

 in both men and women than those resulting from any other method. 

 The errors by this method tail off in the positive direction with a 

 number of errors beyond the 338-412 calories class in the women. 



Obviously, prediction from mean calories heat-production per kilo- 

 gram of body-weight gives bad results in both sexes, and particularly 



