TOSTtwo.raw {TOSTER} | R Documentation |
TOST function for an independent t-test (raw scores)
TOSTtwo.raw( m1, m2, sd1, sd2, n1, n2, low_eqbound, high_eqbound, alpha, var.equal, plot = TRUE, verbose = TRUE )
m1 |
mean of group 1 |
m2 |
mean of group 2 |
sd1 |
standard deviation of group 1 |
sd2 |
standard deviation of group 2 |
n1 |
sample size in group 1 |
n2 |
sample size in group 2 |
low_eqbound |
lower equivalence bounds (e.g., -0.5) expressed in raw scale units (e.g., scalepoints) |
high_eqbound |
upper equivalence bounds (e.g., 0.5) expressed in raw scale units (e.g., scalepoints) |
alpha |
alpha level (default = 0.05) |
var.equal |
logical variable indicating whether equal variances assumption is assumed to be TRUE or FALSE. Defaults to FALSE. |
plot |
set whether results should be plotted (plot = TRUE) or not (plot = FALSE) - defaults to TRUE |
verbose |
logical variable indicating whether text output should be generated (verbose = TRUE) or not (verbose = FALSE) - default to TRUE |
Returns TOST t-value 1, TOST p-value 1, TOST t-value 2, TOST p-value 2, degrees of freedom, low equivalence bound, high equivalence bound, Lower limit confidence interval TOST, Upper limit confidence interval TOST
Berger, R. L., & Hsu, J. C. (1996). Bioequivalence Trials, Intersection-Union Tests and Equivalence Confidence Sets. Statistical Science, 11(4), 283-302.
Gruman, J. A., Cribbie, R. A., & Arpin-Cribbie, C. A. (2007). The effects of heteroscedasticity on tests of equivalence. Journal of Modern Applied Statistical Methods, 6(1), 133-140, formula for Welch's t-test on page 135
## 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 alpha = 0.05, 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.raw(m1=5.25,m2=5.22,sd1=0.95,sd2=0.83,n1=95,n2=89,low_eqbound=-0.384,high_eqbound=0.384)