Backups: rather not [Study Performance]
Hi Mittyr,
Outdated. We abandoned it 20 years ago. Nowadays you should start with the estimated sample size plus some additional subjects according to the expected dropout rate. Even, if you don’t add subjects the loss in power is less than most people think. See this thread; you could loose a lot of subjects until power substantially decreases.
Detlew implemented some useful functions in
In your example (n 22) with five (!) dropouts you still have 72% power.
❝ 1. Backups. […]
❝ For me it looks strange. What do you think about this procedure?
Outdated. We abandoned it 20 years ago. Nowadays you should start with the estimated sample size plus some additional subjects according to the expected dropout rate. Even, if you don’t add subjects the loss in power is less than most people think. See this thread; you could loose a lot of subjects until power substantially decreases.
Detlew implemented some useful functions in
PowerTOST
last October. Try:library(PowerTOSt)
pa.ABE(CV=0.21, minpower=0.7)
In your example (n 22) with five (!) dropouts you still have 72% power.
—
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- Backups; volume of blood during the sampling mittyri 2015-02-03 14:28
- Backups: rather notHelmut 2015-02-03 14:54
- Ehre wem Ehre gebührt d_labes 2015-02-03 16:39
- Backups; volume of blood during the sampling Ohlbe 2015-02-03 23:30
- Backups: rather notHelmut 2015-02-03 14:54