Pete,
On Mon, 2013-03-11 at 13:42 -0500, Pete Meyer wrote:
> My take on it is slightly different - the difference seems to be more
> on
> how the source of error is modeled (although that may dictate changes
> to
> the experiment) rather than essentially depending on how the
> experiment
> was conducted.
>
> Or (possibly) more clearly, systematic error is a result of the model
> of
> the experiment incorrectly reflecting the actual experiment;
> measurement
> error is due to living in a non-deterministic universe.
I see your point.
I want to clarify that reproducing an experiment as far back as possible
is best. Of course it's possible to design an experiment better and
account for pipetting errors. The question is not whether it has to be
done (certainly yes) but whether pipetting error should be considered as
inaccuracy or imprecision when the experiment is not repeated.
One can say it's inaccuracy when it is not estimated and imprecision
when it is. Or one can accept Ian's suggestion and notice that there is
no fundamental difference between things you can control and things you
can potentially control.
IIUC, you are saying that nature of the error should be independent of
my decision to model it or not. Other words, if I can potentially
sample some additional random variable in my experiment, it contributes
to precision whether I do it or not. When it's not sampled, the
precision is simply underestimated. Does that make more sense?
Cheers,
Ed.
--
After much deep and profound brain things inside my head,
I have decided to thank you for bringing peace to our home.
Julian, King of Lemurs
