54o POPULAR SCIENCE MONTHLY. 



The Kesults. Critical. 



Limitations and Sources of Error. — Before examining the results 

 in detail, it is well to consider the limitations under which they were 

 secured and the sources of error to which they may be thought liable. 



Number. — It may be thought that the results lose something of their 

 meaning because only about one blank in three (940* out of 2,700) 

 was returned, but this was considered a very satisfactory showing, be- 

 cause, in the nature of the case, the filling out and return of the blank 

 were not obligatory. Notwithstanding the definite assurances to the 

 contrary contained in the announcement, many students feared that 

 their records would, in some way, be open to the inspction of officials 

 of the university, and therefore balked at making records of their 

 doings in 'black and white,' while more still were either too busy or 

 too lazy and too little interested to make out reports. 



It is a familiar principle, though worth mention in this connection, 

 that the habits of relatively homogeneous groups, such as all those 

 under discussion, may be inferred with considerable certainty from 

 data secured from a relatively small percentage of the members of the 

 groups, provided the representation is typical. The more homogeneous 

 the group, the smaller the data essential for safe induction. 



That our data are typical is attested by two apparently paradoxical 

 facts: (1) When the results are compiled on the basis of classes and 

 courses, it is found that the averages for a given group are closely 

 similar to those of other groups working under similar conditions, 

 e. g., the freshmen and the sophomores in the College of Medicine 

 give 19.72 and 19.30 hours per week, respectively, to outside study, 

 10.30 and 10.37 hours per week, respectively, to amusement, while 

 the freshmen and sophomores in arts give 14.10 and 14.94 hours, 

 respectively, to amusement. (2) In every group we note the pres- 

 ence of some extreme cases which vary widely from the average of 

 the group. Thus, 41 male freshmen average 30.04 hours per week 

 in outside study, yet one freshman records 57.00, and still another but 

 nine hours. In a similar manner, we find that every group contains 

 both the studious and those little given to study, both those who over- 

 indulge in athletics and those who scarcely take physical exercise at 

 all, both leisurely and over-hasty eaters, etc., etc. In short, the reports 

 are representative, f 



* Of this number 45 were rejected, most of them as being incomplete — 

 lacking a day, or a statement of course or class, etc. About 35 per cent, of the 

 undergraduate, 20 per cent, of the graduate, students sent in reports. 



f If any allowance is to be made, possibly we should discount somewhat 

 the average time found for university work in general and outside study in 

 particular, and increase that for amusement or exercise, on the ground that 

 the class of students who are less studiously inclined would be less likely than 



