DISTRIBUTION OF TIME OF CORNELL STUDENTS. 543 



Fidelity of the Reports. — There is no way to know whether the 

 reports are truthful and reliable statements of the students' activities 

 save by the internal evidence of the reports themselves. Judged in 

 this way and in the light of the general interest manifested in the 

 matter at the time, the writer feels confident that a high degree of 

 reliability can be attached to the 895 reports which were admitted to 

 tabulation. 



Accuracy of the Reports. — About one third of the reports contained 

 inaccuracies, chiefly errors in the addition of the totals, or, less often, 

 errors in the number of hours recorded per diem — 25 being a favorite 

 amount ! These errors obviously rendered it impossible to tabulate the 

 reports with any accuracy, so that every one of the 895 reports had to 

 be added anew — an operation requiring some 75 hours of solid work 

 for two persons.* Obvious errors were corrected on the spot; many 

 reports were returned to students for revision, but, in a few cases, 

 where this was not feasible, minor errors were corrected by the writer 

 in accordance with his own judgment. 



Averages and Variations. — For economy's sake the mean variations 

 have been omitted from the tables which follow, for, although they 

 afford a concise index of the uniformity of the individual instances 

 summarized in the average value, their computation would consume 

 more time than they are worth. In place of the mean variation we 

 have recorded the two extremes of individual variation for each group, 

 as ' high ' and ' low,' respectively, while the index of uniformity which 

 would have been supplied by the mean variation is afforded by a com- 

 parison of the average values for the same item in different groups and 

 classes. Thus the high uniformity of the time registered for sleep 

 is shown by comparing the final average for sleep, 7.90 hours daily, 

 with the same average in the table by classes (8.00, 7.96, 7.77, 7.83) 

 or in the table of courses (8.00, 7.86, 8.22, 7.75, 7.90, 7.91, 7.62, 7.76, 

 7.95, 7.74, 8.02). Or, again, the relative uniformity of the results 

 for the various groups and classes can be shown fairly well by com- 

 puting what might be called the ' mean group-variation,' both in terms 

 of absolute hours and in percentage of the final average. Thus, when 

 we compare the averages found for sleep for freshmen arts, sophomore 

 arts, junior arts, senior arts, first year law, etc., through the 39 

 primary groups, with the final average for all students taken collect- 

 ively, we mid (Table 5) a mean variation for these group averages 

 of slightly less than three per cent., while that for meals is eight per 

 cent., and so on. 



The Kesults. Statistical. 



Explanation of the Tables. — With these apologies and explanations 

 we are ready to examine the results themselves. 



* My thanks are due to my wife for her assistance in this laborious under- 

 taking, and in the subsequent task of tabulation. 



