12 BASES FOR CURRICULUM MAKING 



ship is found to equal .500, or in terms of Pearson's formula, 

 .732. If there were no change in positions of the men SG 

 would equal zero and the correlation would be perfect and equal 

 plus 1.00. If the positions were completely reversed the correla- 

 tion would approximate minus 100. If they were purely random, 

 SG equalling 28, the correlation would be zero. This then de- 

 fines the limits and determines the central point of a scale which, 

 if stated in tenths covers twenty steps 

 + 1.000 from -f-1.00 to l.OO. 8 The correlation 



-f- .900 r(fp) .732 obtained above then may be 



conceived of as appearing well up toward 

 the top of this scale and therefore should 

 ' be considered as high in value. With 



I * 3\J^J 



i 4QQ this particular group of thirteen men (as- 



-f- .300 suming the rankings to be perfect) the 



-f- .200 relationship between financial success in 



farming and physical capacity is very 



- 000 marked. 



.100 



O/"W*\ 



' Just what this correlation means may 



400 ^ e determined by considering a question 



^500 like this : "Is physical capacity as defined 



.600 cm page 9 . a cause of financial success, as 



.700 regards this particular group, or is it mere- 



.800 ly a concomitant characteristic that hap- 



pens to rank high. Relationships or cor- 

 relation may be high without necessarily 

 being causal. We should scarcely say 

 that financial success was a cause of physical capacity, yet a 



8. When n=13, as a matter of fact, it is impossible to reach 

 1.00. 



