[R] Use of geometric mean .. in good data analysis

[Rich Shepard]

On Mon, 22 Jan 2024, Martin Maechler wrote:

> I think it is a good question, not really only about geo-chemistry, but
> about statistics in applied sciences (and engineering for that matter).

> John W Tukey (and several other of the grands of the time) had the log
> transform among the "First aid transformations":
>
> If the data for a continuous variable must all be positive it is also
> typically the case that the distribution is considerably skewed to the
> right. In such a case behave as a good human who sees another human in
> health distress: apply First Aid -- do the things you learned to do
> quickly without too much thought, because things must happen fast ---to
> hopefully save the other's life.

Martin,

Thanks very much. I will look further into this because toxic metals and
organic compounds in geochemical collections almost always have censored lab
results (below method dection limits) that range from about 15% to 80% or
more, and there almost always are very high extreme values.

I'll learn to understand what benefits log transforms have over
compositional data analyses.

Best regards,

Rich