EXAMINATIONS, GRADES AND CREDITS. 



373 



But we do not need theorizing so much as facts, which should be 

 secured without delay. In the papers quoted above I have shown that 

 it is possible to transform a qualitative series into one giving measures 

 of differences. If the same thousand examination papers were read 

 and graded independently by ten examiners, the variation in the grades 

 of the same paper by different examiners would give us a measure of 

 the differences between the papers, which would be inversely as the 

 variation of the grades. I have in this way made a curve for the 

 distribution of scientific performance in a selected group, and the 

 same methods should be applied to merit in examinations. 



In the meanwhile I am able to give the grades actually assigned 

 in several cases. The accompanying table shows the grades given 

 to 200 students in each of five courses in Columbia College, and the 

 figure shows the averages and the grades in English A and Mathe- 

 matics A. The average grade is a little above C, the median grade 



Percentage of Students receiving 



Eng. A 

 Eng. B 

 Math. A 

 Hist. A 

 Econ. A 



Average 



£ 



il 



km 



H. 



an 



*$ 



s;: 



+ P.E. +2 P.E. 



Fio. 3- The Distribution of the Average Grades assignee in Five Courses, with the 

 Details for Introductory Courses in English and Mathematics. 



is nearly midway between C and B, and more than two thirds of all 

 the grades are either C or B. Eight per cent, of the grades are 

 A and ten per cent, are F, which approximates closely to the standard 

 recommended above. The average of the grades assigned in these 

 courses does not vary considerably, but the distribution is different. 

 In the courses in English the distribution tends to follow the normal 



