Date:         Wed, 19 Feb 2003 11:49:56 +0100
Reply-To:     fvillamayor-research@ferrergrupo.com
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Frederic Villamayor <fvillamayor-research@ferrergrupo.com>
Subject:      Re: ONEWAY witn MATRIX DATA and SPLIT FILE: a bug?
Comments: To: Asesoría Bioestadística
          <bioestadistica@eresmas.net>
Content-Type: text/plain; charset="iso-8859-1"

Hi,

This happens with version 8.01, too. I've tried to explicitly demand 
        SPLIT FILE LAYERED BY testnum.
before running ONEWAY, and the result is the same. If I try
        SPLIT FILE SEPARATE BY testnum.

only the results for the seconf split group are reported.

Frederic Villamayor
Departamento de Toxicología
C.I.D.F. GRUPO FERRER





Asesoría Bioestadística <bioestadistica@eresmas.net>
Enviado por: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
19.02.03 10:28
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        Asunto: ONEWAY witn MATRIX DATA and SPLIT FILE: a bug?


Hi everybody:

I am working on a big set of summary data (mean, sd & n) for several
groups and several variables. The idea is to perform a oneway ANOVA for
each variable (labeled as "testnum") in the dataset. I have used MATRIX
DATA to create a matrix suitable for ONEWAY... /MATRIX=IN(*). This a
sample of the dataset (just two variables):

MATRIX DATA VARIABLES=testnum rowtype_  group depvar
/SPLIT=testnum /FACTORS=group.
BEGIN DATA
1 MEAN 1 62.80
1 MEAN 2 70.20
1 MEAN 3 79.40
1 MEAN 4 80.20
1 STDDEV 1 6.97
1 STDDEV 2 6.21
1 STDDEV 3 6.24
1 STDDEV 4 6.11
1 N 1 10
1 N 2 10
1 N 3 10
1 N 4 10
2 MEAN 1 72.80
2 MEAN 2 80.20
2 MEAN 3 89.40
2 MEAN 4 90.20
2 STDDEV 1 7.97
2 STDDEV 2 7.21
2 STDDEV 3 7.24
2 STDDEV 4 7.11
2 N 1 15
2 N 2 15
2 N 3 15
2 N 4 15
END DATA.

SPSS syntax guide says that ONEWAY should recognize split groups
specified in matrix data and perform a separate ANOVA for each level of
the splitting variable:

ONEWAY depvar BY group
/STATISTICS=DESCRIPTIVES
/POSTHOC=TUKEY
/MATRIX=IN(*).

This syntax should give 2 descriptives, 2 ANOVA tables, 2 multiple
comparisons tables and 2 homogeneous subsets tables. I get the last (2
homogeneous subsets tables, one for each "testnum" level), but only one
descriptive, ANOVA & multiple comparison (for "testnum"=2).

I have tried this syntax with SPSS 9 and SPSS 11. I get the same results
for both versions of the program.

Is this a bug or should MATRIX DATA be specified in some other way? (I
followed the instructions given in the manual, and, in fact, it looks
like the splitting is recognized, at least partially).

Of course, I know if can do something like:

temporary.
select if (testnum=1).
ONEWAY depvar BY group
/STATISTICS=DESCRIPTIVES
/POSTHOC=TUKEY
/MATRIX=IN(*).

temporary.
select if (testnum=2).
ONEWAY depvar BY group
/STATISTICS=DESCRIPTIVES
/POSTHOC=TUKEY
/MATRIX=IN(*).

And so on.

Or design a "looping macro" to do the job, but curiosity is one of my
defects - I'm a scientist -     ;)

Regards

Marta Garcia-Granero.