Skip to main content
. 2018 Nov 30;5(4):045503. doi: 10.1117/1.JMI.5.4.045503

Table 2.

Nonnull-distribution parameters and their corresponding estimates for the nonequivalence test for the factorial design. Models M1 and M3 each have an approximate noncentral F nonnull distribution with noncentrality parameter λ and degrees of freedom df1=t1=1 and df2. Model M2 has an approximate noncentral, chi-squared nonull distribution with noncentrality parameter λ, and degrees of freedom df1=t1=1. Notes: d = effect size as defined by Eq. (26); t = number of tests, with t=2; r = number of readers; c* = number of cases in the pilot study from which parameter estimates were computed, or the number of cases corresponding to the error variance if parameter values are conjectured; c = number of cases in planned study; σ^TR2, σ^ϵ2, Cov^1, Cov^2, and Cov^3, are OR estimates from a factorial-design pilot study with c* cases, or are conjectured values; NA = not applicable.

Nonnull-distribution parameters:
Model
λ
df2
M1 rd2/2σTR2+σϵ2Cov1+(r1)(Cov2Cov3) [σTR2+σϵ2Cov1+(r1)(Cov2Cov3)]2(στR2+σϵ2Cov1Cov2+Cov3)2/[(t1)(r1)]
M2 rd2/2σϵ2Cov1+(r1)(Cov2Cov3) NA
M3
rd2/2σTR2+σw2
(t1)(r1)=r1
Nonnull-distribution parameter estimates:
Model
λ^
df^2
M1 rd2/2σ^TR2+c*c[σ^ϵ2Cov^1+(r1)max(Cov^2Cov^3,0)] {σ^TR2+c*c[σ^ϵ2Cov^1+(r1)max(Cov^2Cov^3,0)]}2{σ^TR2+c*c[σ^ϵ2Cov^1max(Cov^2Cov^3,0)]}2/[(t1)(r1)]
M2 rd2/2c*c[σ^ϵ2Cov^1+(r1)max(Cov^2Cov^3,0)] NA
M3 rd2/2σ^TR2+c*c[σ^ϵ2Cov^1max(Cov^2Cov^3,0)] (t1)(r1)=r1