bear v1.0.0 - a data analytical tool for ABE in R [🇷 for BE/BA]

posted by ElMaestro  – Denmark, 2008-07-22 16:35 (6125 d 01:25 ago) – Posting: # 2071
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Hi Hsin-ya & Yung-jin,

this effort is much appreciated. Thanks a lot, it must have taken you a lot of time.
Please allow me to ask few questions or give a few comments:
  1. I typed "demoNCAGLM" and got a nice function dump.
    From this I get the impression that the ANOVA in fact is based on lm, not GLM; for example "lm(LnAUC0INF ~ seq + subj + prd + drug, data = TotalData)"?!
    Is this intended - shouldn't it be glm?

  2. The intrinsic R glm function does afair not allow for random effects (in contrast to glm in SAS); analysing datasets with a syntax like "glm(LnAUC0INF ~ seq + subj + prd + drug)" might treat subj as fixed. What's the impact of that?

  3. As far as I remember, both lm and glm are unsafe in cases with imbalance for crossover studies (can't find a ref right now, though, sorry about it). I am under the impression that this type of analysis should be done explicitly with a mixed model (LME, using the REML approach) to ascertain you get the correct sigma.

  4. Although Sums-of-Squares is pretty much a mine field, I think it would be wise to at least implement an option of getting type III SS. Some regulators seem unwilling to accept anything other than type III, while others couldn't care less (I have it on good account :-D). This means that the choice of type III is a safe choice for the time being.
These are just thoughts. I am no expert (neither in statistics nor in BE) I should add.

Best regards,
EM
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