[R-sig-ME] Distribution family for non-negative lower and upper bound values

[Gitu wa Mbui]

I am running generalized additive mixed models on two response variables
separately. Values in response 1 are non-negative and bounded between 1-2,
while response 2 is also non- negative and bounded between 1-3.

In choosing the distribution for response 1, I have subtracted 1 (to
rescale to between 0-1) and logit transformed before fitting the models
with gaussian family.

As for response 2 (non-negative values between 1-3), I have divided the
values by 3 so as to rescale to between 0-1, before logit transforming and
fitting with gaussian family.

Does this sound like a good approach? if not what are the alternatives,
considering:
- responses 1&2 are not proportions
- I am using lme4 version (gamm4) which is limited on the number of
families that can be fit
- histograms of both responses are pretty flat (non skewed and don't look
anywhere near normal distribution

~ Gitu

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