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

posted by d_labes  – Berlin, Germany, 2020-11-25 15:07 (59 d 21:40 ago) – Posting: # 22085
Views: 1,578

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

Complete thread:

Activity
 Admin contact
21,310 posts in 4,445 threads, 1,489 registered users;
online 2 (0 registered, 2 guests [including 2 identified bots]).
Forum time: Sunday 12:48 CET (Europe/Vienna)

Every man gets a narrower and narrower field of knowledge
in which he must be an expert in order to compete with other people.
The specialist knows more and more about less and less
and finally knows everything about nothing.    Konrad Lorenz

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5