Re: BRM article: DIY bootstrapping

Posted by Art Kendall on Mar 21, 2023; 2:41pm
URL: http://spssx-discussion.165.s1.nabble.com/BRM-article-DIY-bootstrapping-tp5741122p5741123.html

Thank you.

I'll try to take a close look at the article and extension.

In 1971, the SIFT (Statistics by Interaction with Files from a Terminal) package had a module called Mother which could generate correlation matrices that had a particular factor structure. IIRC it could also generate practice datasets for descriptive stats.

I have long advocated using SPSS to generate examples simulating  the confidence intervals from random
data with known parameters.

INPUT PROGRAM is useful for (a)simulating many things: cards, dice, etc.  (b)for developing better understanding of obtained probabilities, (c) for handling unusual distributions.

For example, wrap the syntax below in an outer loop look at the kind of IQ scores that could come from sets of 40 cases.
new file.
input program.
   loop id = 1 to 40.
      compute IQ = rnd(rv.normal(100,15)).
      end case.
   end loop.
   end file.
end input program.
execute.

* for all such simulations.
*paste your syntax here to save the results in a data set .
* then see where your obtained mean falls in the set of simulated results.
* how does that compare to the results from the usual procedures

I do not recall when it was introduced, but parallel analysis is and extremely useful tool in approximating a stopping rule in FACTOR.  With today's computers is trivial to generate a million sets of eigenvalues from randomized data with the same number of cases and variables.  One can then see how the obtained eigenvalues compare to the distribution of eigenvalues from the simulation.