348 ILLINOIS STATE ACADEMY OF SCIENCE 



the amount retained per minute of time invested in learn- 

 ing by each subject. A summary of the results follows: 

 The figures in the second column give the average learn- 

 ing scores of the quartiles. If all the questions had been 

 answered correctly, the score would have been 100%. 

 The figures in the third column give the average reten- 

 tion scores after one week; those in the fourth column, 

 the average learning times in minutes. The figures in 

 the fifth and sixth columns give the average learning and 

 retention scores per minute of time spent in learning 

 (M. L. T.), and those in the seventh column give the 

 average percentages of retention. 



RATIOS OP RETENTION TO LEARNING IN THE SECOND 



Avs. 48 43 11.3 4.5 4.0 90 19.2 



The quartile which learned the most took the least 

 time for study. So far as quartile averages go, the 

 higher the learning ability the less time needed for study, 

 in spite of the greater gains from study. With the in- 

 crease in the difficulty of the material the range between 

 the best and the poorest learners increases. Whereas in 

 the first selection the fastest quartile learned two and 

 one-half times as much as the slowest, in the second 

 selection the fastest quartile learned nearly five times 

 as much as the slowest. The second selection was in- 

 tentionally somewhat difficult for the class. An idea 

 of how difficult it was may be gained from the fact that 

 the average mark of the whole class in learning was 48%, 

 100 % being a perfect answering of all questions. We 

 are most interested in the percentages of retention, 

 however. The first, third, and fourth quartiles retain 

 about the same percents, 91, 94, and 94; the second quar- 

 tile retains 83%. The standard deviations are large in 

 the two slowest quartiles because when a person learns 

 very little, an ability to answer one question more or 

 less greatly changes the ratio of retention to learning. 



