TABLE 1
NUMBER OF SUBJECTS, AGE, SEX, AND NUMBER OF JUDGMENTS
| Males | ||
| Age | No. of subjects | No. of judgments |
| 17 yrs. | 16 | 256 |
| 18 | 27 | 432 |
| 19 | 40 | 639 |
| 20 | 67 | 1071 |
| 21 | 50 | 800 |
| 22 | 35 | 560 |
| 23 | 16 | 256 |
| Totals | 251 | 4014 |
| Interval | No. of judgments | |
| 18" | 1004 | |
| 36" | 1003 | |
| 72" | 1003 | |
| 108" | 1004 | |
| Total | 4014 | |
| Females | ||
| Age | No. of subjects | No. of judgments |
| 17 yrs. | 73 | 1160 |
| 18 | 57 | 911 |
| 19 | 64 | 1024 |
| 20 | 80 | 1280 |
| Totals | 274 | 4375 |
| Interval | No. of judgments | |
| 18" | 1092 | |
| 36" | 1094 | |
| 72" | 1096 | |
| 108" | 1093 | |
| Total | 4375 | |
A general survey of the individual records, all of which for any one year and sex were tabulated, for convenience of examination, on a single large sheet of coördinate paper, showed that the judgments vary within a wide range and are very inexact. Table 2 exhibits the number of correct judgments for each sex, interval, and filling. Of the 4014 male judgments only 96 (2.39%) were correct; of the 4375 female judgments only 46 (1.05%) were correct. The number of correct judgments decreases as the length of the interval increases. For the 18-second intervals there were 7.37% for the males, 2.48% for the females, while for the 108-second intervals there were only 0.10% and 0.37% respectively.