Re: [bug #48040] GLM produces wrong output

[John Darrington]

On Sat, May 28, 2016 at 09:31:25PM -0500, Alan Mead wrote:
     John,
     
     Sorry for the delay.
     
     Attached is the SPSS output.
     
     I also ran PSPP and I notice that PSPP calculates negative SS for this
     analysis, which produces negative MS, Negative F's, etc. 
     
     If I add "select if( not sysmis(agree_score))." before GLM, I reproduce
     the SPSS output.  Seems like not treating missing values is part (or the
     entirety?) of the problem? I wondered if perhaps SPSS 24 might mark
     missing values in a new way that is confusing to PSPP? But that's pure
     hypothesizing...
     
     
Thanks Alan,

You are right - this is entirely due to missing values.  I'm somewhat relieved
that it is not something more fundamental.

But the problem I see now is that SPSS does not document how it treats missings.

Perhaps you could do some experiments.  For example, do missing values in the 
factor variables
get treated as a separate factor value or does the case get simply dropped?

And what about the dependent variables? If there are say 2 dependent variables 
and one
is missing  what happens then?  Is the case dropped for both anayses or just 
the one that is missing?


J'



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