Inflated type I error with fixed widened limits? [RSABE / ABEL]

posted by d_labes  – Berlin, Germany, 2020-11-25 16:07 (738 d 13:57 ago) – Posting: # 22085
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Dear Helmut,

❝ What happens if we pre-specify the widened acceptance range and discover in the study that CVwR ≤30? Assess the study for the conventional AR of 80.00–125.00%? IMHO, that means we have a data-driven decision – which might be false and result in an inflated type I error.


Correct.

❝ I performed simulations acc. to my understanding of the GL:

[image]


❝ CVwR = CVwT = 30%, balanced 4-period 2-sequence full replicate design (TRTR|RTRT), n = 40 (81% power for θ0 = 0.90), 106 studies with θ0 = 1.25: ~20.6% passed…


Confirmed! At least in magnitude.
My result: 20.46% passed.
Quick and dirty captured code from power.scABEL.sds.

Regards,

Detlew

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