sequence stratified WMW test [Nonparametrics]
Hi Croosov,
You might be able to do just that. Let's say we model something like:
Observed Tmaxi = Treatmentj + error
where Tmaxi is the i'th Tmax observation and Treatmentj denotes the j'th treatment given for the i'th Tmax observation. In ordinary linear models we use an error that is normal with mean zero and some variance and the fit corresponds to tweaking the constants so that the variance is minimized (then that's the solution that is most likely).
For Tmax, as Helmut says, we probably do not have a normal error and we might not have a qualified guess about its distribution. If you happen to have a good guess for the error distribution then you can specify that distribution as the link function for the model (hence the term generalized: the error can be anything, not just normal). But the next issue will then be what do you do with the model once it has been fitted? Is there a relevant test? If there is, is there a relevant interpretation of the test?
It is all beyond me, to be honest. To use a term from Helmut's vocabulary: It's wacky.
And to me it is more wacky than useful.
❝ While I was reading the literature you recommended I wondered if it isn't possible to use a generalized linear model? If not why?
You might be able to do just that. Let's say we model something like:
Observed Tmaxi = Treatmentj + error
where Tmaxi is the i'th Tmax observation and Treatmentj denotes the j'th treatment given for the i'th Tmax observation. In ordinary linear models we use an error that is normal with mean zero and some variance and the fit corresponds to tweaking the constants so that the variance is minimized (then that's the solution that is most likely).
For Tmax, as Helmut says, we probably do not have a normal error and we might not have a qualified guess about its distribution. If you happen to have a good guess for the error distribution then you can specify that distribution as the link function for the model (hence the term generalized: the error can be anything, not just normal). But the next issue will then be what do you do with the model once it has been fitted? Is there a relevant test? If there is, is there a relevant interpretation of the test?
It is all beyond me, to be honest. To use a term from Helmut's vocabulary: It's wacky.
And to me it is more wacky than useful.
—
Pass or fail!
ElMaestro
Pass or fail!
ElMaestro
Complete thread:
- which test for tmax (> 2x2crossover design)? Croosov 2014-08-26 15:26
- sequence stratified WMW test d_labes 2014-08-26 16:19
- sequence stratified WMW test Croosov 2014-09-24 17:58
- GLM on ranks? Helmut 2014-09-24 20:00
- sequence stratified WMW testElMaestro 2014-09-24 21:27
- sequence stratified WMW test Croosov 2014-09-24 17:58
- sequence stratified WMW test d_labes 2014-08-26 16:19