Dear all
First of all apologies for the off-topic question and for not respecting
the other points.
Second, thanks for your advice and opinion I will definitely consult a
statistician.
Regards,
Alessandra
On Sun, May 10, 2020 at 4:57 PM Abby Spurdle <spurdl...@gmail.com> wrote:
> Well, this is 100% off-topic...
> And I wasn't planning to answer the OP's question.
>
> However, I disagree with your answer.
>
> > There is no requirement that the dependent variable in a "regression"
> type
> > estimation follows a gaussian distribution.
>
> False.
> It's depends on what type of '"regression" type estimation' one uses,
> among other things.
>
> > You need a model of the
> > process and then use an estimation technique to estimate your model. If
> > effects in your model are additive do not use a log transformation. If
> > effects are multiplicative then use a log transformation.
>
> The main question is, does the model satisfy the *assumptions*.
>
> > The choice
> > should be determined by the mechanics of the problem and not by the
> > statistics.
>
> While a mechanistic understanding is definitely valuable...
> If the criteria for a good model vs a bad model, was whether the model
> was consistent with mechanistic theory/understanding, then nearly
> every statistical model I've seen would be a bad model.
> I would say, a good model is one that is useful...
>
> > If you do use a log transformation the trying to reverse the
> > process using an exponential transformation will be biased.
> > The extent of
> > that bias depends on your problem and it would not be possible to
> estimate
> > the significance of the bias without a much greater knowledge of the
> > process and data.
>
> Never heard of this before...
> But I do note back-transformation is not trivial, and I'm not an
> expert on back-transformations.
>
> > I would suggest that you consult a competent
> > statistician.
>
> I agree on that part...
>
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
