[R] (g)lm ordinal or scaled values?

Knut Krueger Knut-krueger at einthal.de
Mon May 8 16:35:34 CEST 2006

There is a difference in the p- value from   0.000 and 0.012 when I am 
using SPSS.
0.000 when I am using the independent variable as scaled 0.012 if I am 
using the variable as  ordinal.

The independent variable is ordinal but it seems that R is using the 
variable as an scaled, because the P- Value is computed with 4.66e-06

so I am not sure which description I am misunderstanding:
Covariates. Scale predictors <javascript:popup(N2C5F1_term,N2C5F1_def);> 
should be selected as covariates 
<javascript:popup(N2B079_term,N2B079_def);> in the model. Within 
combinations of factor levels (or cells 
<javascript:popup(N2AE3F_term,N2AE3F_def);>), values of covariates are 
assumed to be linearly correlated with values of the dependent variables.
(A variable can be treated as scale when its values represent ordered 
categories with a meaningful metric, so that distance comparisons 
between values are appropriate. Examples of scale variables include age 
in years and income in thousands of dollars.)

Factors. Categorical <javascript:popup(N2AD73_term,N2AD73_def);> 
predictors should be selected as factors 
<javascript:popup(N2B481_term,N2B481_def);> in the model. Each level 
<javascript:popup(N2B937_term,N2B937_def);> of a factor can have a 
different linear effect on the value of the dependent variable.(A 
variable with a discrete number of values; an ordinal or nominal 
variable. Categorical variables are often used as grouping variables or 

The data : http://biostatistic.de/temp/testr.csv

lm.data<-lm( dependent ~ var2,family = gaussian)

I don't know whether anybody could explain me the difference between 
SPSS and R results but if there are different results then one of them 
is wrong :-(
And I do not know which of them.
I hope I explained the problem understandable

Regards Knut

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