Re: Confidence interval is mathematically equivalent to hypothesis test

[Dr. Oliver Walter]

I don't think that PSPP can produce bar charts with confidence intervals 
or something similar (bar charts for means aren't the best idea 
anyway).  I think it is only possible to split the data file to compare 
groups and then calculate confidence intervals for the mean for these 
groups.

Command:

SORT CASES BY var1 [var2].
SPLIT FILE LAYERED BY  var1 [var2].

T-TEST /TESTVAL=0
    /VARIABLES= dependent variables    /MISSING=ANALYSIS
    /CRITERIA=CI(insert your confidence level here, e.g. 0.95).

Then you can use the means and the bounds of the confidence intervals to 
draw your own graphs outside PSPP. I think that this is the better way 
because the quality of the charts is not very good in PSPP and I cannot 
recommend them to be used in any thesis or research paper. Or you could 
use another statistical software which is able to do what you need.


Am 13.10.2018 um 07:24 schrieb Werner LEMBERG:
> > It seems to be a mixed ANCOVA with a within-subjects factor called
> > "Location", a between-subjects factor called "Group" and a covariate
> > "Age".  I think that the GLM command in PSPP is not able to compute
> > such an analysis.  GLM can only compute between-subjects designs in
> > PSPP (cf. PSPP manual, p. 143).
> Yes.  As mentioned before, however, I'm not interested in the complete
> analysis but only in reproducing the bar diagram.  Note that the
> printed SPSS report doesn't ever mention a CI value; it is only used
> for the error bar in the diagram – which are huge in this particular
> case, BTW.  I hope it is safe to assume that the error bars can be
> approximated by the simplest approach (i.e., based on a model for few
> samples) in case SPSS uses different values.
>
> So: Is there a command in PSPP that directly gives me a standard CI
> value?  Or does I have to cook it up using the formula already
> mentioned in this thread?
>
>
>      Werner