# [R] Different result of multiple regression in R and SPSS

Dimitri Liakhovitski dimitri.liakhovitski at gmail.com
Wed Jul 20 00:41:09 CEST 2011

```I don't think SPSS does anything with the variables you enter there.
Have you entered it as numeric?
Have you entered gender as numeric in R?

On Tue, Jul 19, 2011 at 6:11 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> Answer: Contrasts, i.e. the parameterization of the categorical variable(s) df.
>
> ?contrasts may be of some help, but you really need to do some
> background studying of the linear models principles involved. Googling
> may provide tutorials. Also searching the mail archives, e.g.:
>
> https://stat.ethz.ch/pipermail/r-help/2009-February/187479.html
>
> -- Bert
>
> On Tue, Jul 19, 2011 at 2:39 PM, J. <seoulseoulseoul at gmail.com> wrote:
>> Hi, I am trying to do a simple multiple regression analysis that has one
>> nominal variable (gender) and three numeric variables as independent
>> variables and one numeric variable as dependent variable.
>>
>> So, I got a formula like this:
>> summary(out.3 <- lm(scale(DV) ~  gender + scale(IV.1) + scale(IV.2) +
>> scale(IV.3))
>>
>> I tried to compare the outcome in R with the outcome in SPSS and found the
>> results are different!
>> I found that R and SPSS have the exact same outcome when every variable is
>> numeric; however, whenever I included "gender (0/1)" variable in the
>> equation, the result become different.
>>
>> I guess that SPSS automatically treat gender as a numeric variable and
>> standardize it when running analysis. So, I tried to change "gender" to a
>> numeric variable and ran analysis but the results were still not identical.
>>
>> What is the problem here and what is the right way to do this analysis?
>> Thanks,
>>
>> Jay Yang
>>
>> --
>> View this message in context: http://r.789695.n4.nabble.com/Different-result-of-multiple-regression-in-R-and-SPSS-tp3679423p3679423.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> "Men by nature long to get on to the ultimate truths, and will often
> be impatient with elementary studies or fight shy of them. If it were
> possible to reach the ultimate truths without the elementary studies
> usually prefixed to them, these would not be preparatory studies but
> superfluous diversions."
>
> -- Maimonides (1135-1204)
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
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