I think John is saying that in SPSS/PSPP you need to use a statistical
function to generate statistical results like a CI. For example, T-TEST
will produce a 95% CI for the mean difference in independent-samples
t-tests. Other routines may provide other confidence intervals.

But maybe you want to use compute to create a variable for each case:

compute LB = x - 1.96 * 10.1/sqrt(31).
compute UB = x + 1.96 * 10.1/sqrt(31).

This creates variables LB and UB for all cases in your data file and you
need to supply Z, mean, SD, and n.

Connecting that to your query about AGGREGATE, which takes groups of
cases (defined by unique values on BREAK) and creates summary stats, you
could use AGGREGATE to create mean, SD and n in the above equation and
then use those compute statements to calculate the bounds of the CI for
the groups of cases. So, you would have to do two steps. First an
AGGREGATE command that creates mean, SD and n, followed by the two
computes above.

You would end up with a dataset containing the mean, sd, n, LB, and UB
for each group (defined by a unique value of BREAK) in the original dataset.

Hopefully you only have one variable (or a very few) in the data that
you want this on, because you have to create mean, SD and n for each
variable.

-Alan

On 10/12/2018 8:01 AM, Mark Hancock wrote:
> I unfortunately don't know enough about PSPP syntax to suggest how to
> do this, but a CI is *not* always associated with a hypothesis and can
> be calculated from just a mean and SD (and a cumulative distribution
> function, which is typically the normal one). Typically the formula is
> something like:
>
> mean ± z(SD/sqrt(n)), where z is from the CDF.
>
> On Fri, Oct 12, 2018 at 6:29 AM John Darrington
> <j...@darrington.wattle.id.au <mailto:j...@darrington.wattle.id.au>>
> wrote:
>
>     The confidence interval is a concept associated with a hypothesis.
>     If it's the confidence interval on the test for a mean value,
>     typically you
>     would get that by using a T-Test.
>
>
>     On Fri, Oct 12, 2018 at 10:40:22AM +0200, Werner LEMBERG wrote:
>
>          Folks,
>
>
>          I would like to get a 95% confidence interval so that I could
>     use it
>          in AGGREGATE, e.g.,
>
>            AGGREGATE OUTFILE * MODE ADDVARIABLES
>              /BREAK=...
>              /Mean = mean(V)
>              /CI = ci(V, 0.95)
>
>          What must I do to get the result of my hypothetical `ci'
>     function?
>          I'm a PSPP novice, so maybe there is a better solution than
>     AGGREGATE
>          ??? what I ultimately want is to emit the confidence interval
>     of a
>          variable to a CSV file using SAVE TRANSLATE.
>
>
>              Werner
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-- 

Alan D. Mead, Ph.D.
President, Talent Algorithms Inc.

science + technology = better workers

http://www.alanmead.org

"You're an interesting species. An interesting mix. 
You're capable of such beautiful dreams, and such 
horrible nightmares. You feel so lost, so cut off, 
so alone, only you're not. See, in all our 
searching, the only thing we've found that makes 
the emptiness bearable, is each other."

-- Carl Sagan, Contact

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