| Date: | Fri, 18 Apr 2008 11:33:25 -0300 |
| Reply-To: | Hector Maletta <hmaletta@fibertel.com.ar> |
| Sender: | "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU> |
| From: | Hector Maletta <hmaletta@fibertel.com.ar> |
| Subject: | Re: weight by syntax |
|
| In-Reply-To: | <E0428445172CB7469BF187FF4D005149078370AB@CHIEMAIL1.spss.com> |
| Content-Type: | text/plain; charset="us-ascii" |
Of course weighting in one variant and not weighting in the other variant
will affect the results. The same would happen with any procedure: a
weighted crosstabs will be different that an unweighted one. But weighting
per se (applied in both variants) would not affect anything regarding the
specific problem posed in this thread.
Hector
-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of
Oliver, Richard
Sent: 17 April 2008 21:13
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: Re: weight by syntax
Weight will definitely affect your results unless the value of the weight
variable is a constant. Consider the following very simple example:
data list list /x y z.
begin data
1 2 1
2 4 1
3 1 5
4 5 1
end data.
REGRESSION
/DEPENDENT x
/METHOD=ENTER y.
WEIGHT BY Z.
REGRESSION
/DEPENDENT x
/METHOD=ENTER y.
The WEIGHT command basically says: Treat every case as if there were N cases
with these values, where N is the value of the WEIGHT variable. In this
case, once you weight the data, there are five cases with a values of 3 and
1 for for x and y respectively instead of just one.
________________________________
From: SPSSX(r) Discussion on behalf of jimjohn
Sent: Thu 4/17/2008 4:43 PM
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: Re: weight by syntax
thanks guys let me try to explain this problem better.
so when i implement the syntax written in my original comment:
my output gives me nine different regression outputs, for example:
for balbucket 1, i get the following 3 regression outputs:
redrate_m vs saving3, redrate_m vs saving3 and saving3_sq, and redrate_m vs
saving3, saving3_sq, age
and so i get those same three regressino models for balbucket2 and for
balbucket3.
now without using any syntax, i want to get the same regression output
result that i got for balbucket 1: redrate_m vs saving3, saving3_sq, and age
so i go select cases -> balbucket = 1. then i go to the regression and i
should be getting the same output but i dont. here is the syntax that shows
up from what i do:
USE ALL.
COMPUTE filter_$=(balbucket = 1).
VARIABLE LABEL filter_$ 'balbucket = 1 (FILTER)'.
VALUE LABELS filter_$ 0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE.
REGRESSION
/MISSING LISTWISE
/STATISTICS COEFF OUTS R ANOVA
/CRITERIA=PIN(.05) POUT(.10)
/NOORIGIN
/DEPENDENT redrate
/METHOD=ENTER saving3 saving3_sq age.
so im not understanding why i get a different regression output for
balbucket1 regression. the one thing i dont really understand in the syntax
i used in the beginning was WEIGHT BY so im thinking this must have
something to do with why the results are different. any ideas? thanks.
Hector Maletta wrote:
>
> No time to go into the problem right now, but just an offhand comment:
> Weight, I believe, has nothing to do with it. Each case has a weight, and
> the weight of a case does not change when you filter cases or split the
> file. Filter executes a binary decision (selects a case if the condition
> if
> the filter variable equals 1, and leaves it out if the filter variable
> does
> not equal 1). Since BALBUCKET has three possible values, this may be a
> source of differences with SPLIT FILE.
> Hector
>
>
> -----Original Message-----
> From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of
> jimjohn
> Sent: 17 April 2008 17:36
> To: SPSSX-L@LISTSERV.UGA.EDU
> Subject: weight by syntax
>
> can someone plz help me with this, im trying to understand this syntax: i
> thought this is just a multiple regression model with redrate_m vs
> (saving3,
> saving3_sq, age) for different values of balbucket (either 1, 2, or 3).
> but
> if i just filter balbucket and run the regression model i get different
> output. so im just wondering what does this WEIGHT BY rembal do to change
> my
> regression output? thanks so much.
>
> WEIGHT
> BY rembal .
> SORT CASES BY balbucket .
> SPLIT FILE
> LAYERED BY balbucket .
> REGRESSION
> /MISSING LISTWISE
> /STATISTICS COEFF OUTS R ANOVA CHANGE
> /CRITERIA=PIN(.05) POUT(.10)
> /NOORIGIN
> /DEPENDENT redrate_m
> /METHOD=ENTER saving3 /enter saving3_sq /enter age .
> --
> View this message in context:
> http://www.nabble.com/weight-by-syntax-tp16754311p16754311.html
> Sent from the SPSSX Discussion mailing list archive at Nabble.com.
>
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Sent from the SPSSX Discussion mailing list archive at Nabble.com.
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