Lakens / TOSTER

TOST equivalence test and power functions
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finally fix 0.43 vs 0.48 bounds issue in example text everywhere. #47

Open Lakens opened 4 years ago

Lakens commented 4 years ago

Eskine (2013) showed that participants who had been exposed to organic

food were substantially harsher in their moral judgments relative to

those exposed to control (d = 0.81, 95% CI: [0.19, 1.45]). A

replication by Moery & Calin-Jageman (2016, Study 2) did not observe

a significant effect (Control: n = 95, M = 5.25, SD = 0.95, Organic

Food: n = 89, M = 5.22, SD = 0.83). Following Simonsohn's (2015)

recommendation the equivalence bound was set to the effect size the

original study had 33% power to detect (with n = 21 in each condition,

this means the equivalence bound is d = 0.48, which equals a

difference of 0.384 on a 7-point scale given the sample sizes and a

pooled standard deviation of 0.894). Using a TOST equivalence test

with default alpha = 0.05, not assuming equal variances, and equivalence

bounds of d = -0.43 and d = 0.43 is significant, t(182) = -2.69,

p = 0.004. We can reject effects larger than d = 0.43.

TOSTtwo(m1=5.25,m2=5.22,sd1=0.95,sd2=0.83,n1=95,n2=89,low_eqbound_d=-0.43,high_eqbound_d=0.43)