[S] Sampling in bootstrap()

Marc Feldesman (feldesmanm@pdx.edu)
Wed, 25 Feb 1998 11:26:23 -0800


I'm trying to understand the default sampling scheme used in the
bootstrap() function. I can best explain my question with a problem.

In an earlier message, I explained that I was trying to replicate an
analysis a statistician colleague and I published two years ago in which we
used bootstrapping to put empirical confidence limits on an F-statistic
derived from a one-way ANOVA involving three groups. Numerous users
generously helped me figure out the appropriate syntax for replicating the
analysis. I've now done this and the results look more or less like what
they did when we published the paper two years ago.

Now, for my question. The original sample had a total of 55 cases
distributed as 13 in one group, 15, in the second group, and 27 in the
third group. The original (published) bootstrap analysis simply took
random samples of 55 (with replacement of course) and assigned the first 13
randomly selected cases to group 1, the next 15 cases to group 2, and the
last 27 cases to group 3.

Is this an accurate interpretation of what bootstrap() does using the
default sampling scheme?

Thanks.
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