Adaptive TSD vs. “classical” GSD [Two-Stage / GS Designs]
Hi Hötzi,
It is a great question, and I will not offer a definitive answer, but I will volunteer an opinion
You can look at it this way: A GSD is a kind of TSD where you make assumptions about both the GMR and the CV (you use the anticipated ones, not the observed ones) when you transit from stage 1 to stage 2. That anticipated pair of CV+GMR is exactly the (or a) combo that naïvely doubles the sample size. Simple but extremely rigid.
Thereby the GSDs should be considered a relic from bygone ages when computers were not fast enough to allow simulations to achieve what Potvin et al. have done.
❝ Given all that: Why should one use a GSD instead of a TSD?
It is a great question, and I will not offer a definitive answer, but I will volunteer an opinion

You can look at it this way: A GSD is a kind of TSD where you make assumptions about both the GMR and the CV (you use the anticipated ones, not the observed ones) when you transit from stage 1 to stage 2. That anticipated pair of CV+GMR is exactly the (or a) combo that naïvely doubles the sample size. Simple but extremely rigid.
Thereby the GSDs should be considered a relic from bygone ages when computers were not fast enough to allow simulations to achieve what Potvin et al. have done.
—
Pass or fail!
ElMaestro
Pass or fail!
ElMaestro
Complete thread:
- Adaptive TSD vs. “classical” GSD Helmut 2015-11-27 19:05 [Two-Stage / GS Designs]
- Adaptive TSD vs. “classical” GSDElMaestro 2015-11-27 19:54
- “classical” GSD - E[n] d_labes 2015-11-30 11:15
- Apples are pears by comparing the weight Helmut 2015-12-01 16:35
- Apples are pears by comparing the weight d_labes 2015-12-03 09:16
- Apples are pears by comparing the weight Helmut 2015-12-03 13:10
- Oranges d_labes 2015-12-03 13:56
- Apples are pears by comparing the weight Helmut 2015-12-03 13:10
- Apples are pears by comparing the weight d_labes 2015-12-03 09:16
- Apples are pears by comparing the weight Helmut 2015-12-01 16:35
- Adaptive TSD vs. “classical” GSD Ben 2015-12-02 19:27
- Adaptive TSD vs. “classical” GSD Helmut 2015-12-03 03:11
- “classical” GSD alpha's d_labes 2015-12-03 09:47
- N sufficiently large‽ Helmut 2015-12-03 14:56
- An other one with 0.0304 d_labes 2015-12-03 16:15
- An other one with 0.0304 Helmut 2015-12-03 16:26
- An other one with 0.0304 d_labes 2015-12-03 16:15
- N sufficiently large‽ Helmut 2015-12-03 14:56
- Adaptive TSD vs. “classical” GSD Ben 2016-01-10 12:43
- “classical” GSD alpha's d_labes 2015-12-03 09:47
- Adaptive TSD vs. “classical” GSD Helmut 2015-12-03 03:11