Kelly wants to know if the amount of time someone sleeps per night is related to their stress. She therefore recruits a sample of 500 classmates from her university and measures sleep length in minutes on one night and measures stress on a 1-7 scale the next day. She then performs a dependent-measures t-test to assess the effect of sleep length on stress. She finds no significant effect of the amount of time someone sleeps on their stress level the next day,t(998) = 1.25,p<.05, two tailed,R2= 0.001, which is a very small effect size.