this study on pre-schoolers N = 44 | Hattori’s study on pre-schoolers N = 459 | z | p | |||
M | SD | M | SD | |||
wake-up time | 7:06 | 30 min | 7:07 | 25 min | −1.579 | 0.114 |
bedtime | 21:36 | 41 min | 21:17 | 38 min | 0.316 | 0.752 |
sleeping duration | 9.5 hour | 36 min | 9.8 hour | 45 min | 1.769 | 0.077 |