Re: Bootstrap confidence intervals

XIC@CU.NIH.GOV
Fri, 29 Jul 94 11:42:35 EDT


J.E.H. Shaw (29 July 1994) writes:

> The idea of using the bootstrap to obtain CI's has always
> struck me as perverse, since one is simultaneously assuming:
>
> (A) (for bootstrapping) The underlying population distribution is
> precisely the same as the observed sample distribution.

I don't think this is what we are assuming. I like the
explanation in Peter Hall's recent book on the bootstrap
(I don't recall the exact title). Bootstrapping is based
on an analogy:

Bootstrap sample is to original sample
as
original sample is to population.

Peter Hall gives an example using Russian dolls
to illustrate this.

>
> (B) (to get a CI) The underlying population distribution is not
> necessarily the same as the observed sample distribution.
>

But this is accounted for in the calculation of the CI.

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