StdtislH'al finu'Htif/atiauM 



389 



case to mark from the mean or median. It Ih not (juito clear in this case why 

 there should not be negative marks for those who fell short of mediocrity. 

 Oalton then provides marks for each rank alwve 50°/^ or again for the deviate. 

 In the latter case the full nuniljer of murks is supposed to be reached by 

 a grade 99"99. Next he draws up a table in which the total marks for 

 physical efticiency are assumed to be 10 and are supposed to be assigned in 

 dimsreiit proportions to rank and to aljsolute achievement, Le. to aeviate 

 from mediocrity. His table {B. A. R. p. 476) is as follows: 



i 



It is clear that Galton is compounding what every schoolmaster has to 

 consider, namely: "place in class" with "marks in examination," or indeed 

 "place" and "marks in examination." If the distribution were normal the 

 marks would be readily deducible from "place" in examination. Considering 

 what wide dift'erences occur between the top individuals — for example in the 

 old Cambridge Mathematical Tripos system — and what slight diflferences 

 between mediocre individuals, one is inclined to doubt the legitunacy of mark- 

 ing by rank. This point was recognised, I think, by Galton later when he 

 endeavoured to estimate the average differences between individuals arranged 

 according to rank. However the teble is suggestive and we leave it to the 

 consideration of the educationalist. 



Galton supposes the chief physical measurements to have been reducetl 

 for the class under examination to percentile scales, such as in the table on our 

 p. 376. He gives a rather clear diagram of the absolute values for males and 

 females at each rank for seven characters on p. 29'. In some of the chai-acters 

 it would be desirable for rapid and safe interpolation to insert a few more 

 values of the deviate. 



boys. Their average tlifference in jutlginent was 8-75 °/^ of the maximum marks. Ninete<>n of 

 tlie boys were sul)scquently examiiietl in English Kssay, and the essays submitted to two inde- 

 pendent examiners. The average difference was now 16-7°/^ of the maximum mark.s. The 

 experiments seem to have been imdertaken at Galton's suggestion and are used by him as an 

 argument that physical teat marks can !» as accumtely determined as marks for literary work. 

 Some years ago the present writer reported on the marking statistics of the London Matricula- 

 tion Examination, ile was startled to find that the relative personal equation of examiners in 

 history, languages and literature was very greatly larger than the relative personal equation of 

 examiners in brunches of science ; and that no systematic method of correcting for this personal 

 equation had been adoptetl. Thus a candidate's chance of passing depended largely on the 

 examiner to whom his paper wa.s allotte<l! It would appear therefore that the choice of an 

 English e».say for comparison of marking differences was rather unfortunate. 

 ' See Nature, Vol. XL, pp. 650 and 051. 



