What is the difference between covariates or factors, in a ordinal regression?

[Sushma Dhital]

I read that independent categorical variable should be treated as factors, is it true?

[Bruce Weaver]

Post by Sushma Dhital
I read that independent categorical variable should be treated as factors, is it true?

Yes, Factors are categorical explanatory variables (e.g., sex, marital status), and Covariates are continuous (or at least quantitative) explanatory variables (e.g., age, body weight).

[Rich Ulrich]

On Mon, 27 Feb 2017 13:56:11 -0800 (PST), Bruce Weaver

Post by Bruce Weaver

Post by Sushma Dhital
I read that independent categorical variable should be treated as factors, is it true?

Yes, Factors are categorical explanatory variables (e.g., sex, marital status), and Covariates are continuous (or at least quantitative) explanatory variables (e.g., age, body weight).

Of course -- you can code up the dummy variables for
the factors and do the whole analysis of ANOVA with a
regression program. That is what all modern stat-packages
do, internally.

If you want to think of one factor as being in the model as
a logical "covariate" (with 1 or more d.f.), that is fine.

[Lijun Zhao]

Post by Rich Ulrich
On Mon, 27 Feb 2017 13:56:11 -0800 (PST), Bruce Weaver

Post by Bruce Weaver

Post by Sushma Dhital
I read that independent categorical variable should be treated as factors, is it true?

Yes, Factors are categorical explanatory variables (e.g., sex, marital status), and Covariates are continuous (or at least quantitative) explanatory variables (e.g., age, body weight).

Of course -- you can code up the dummy variables for
the factors and do the whole analysis of ANOVA with a
regression program. That is what all modern stat-packages
do, internally.
If you want to think of one factor as being in the model as
a logical "covariate" (with 1 or more d.f.), that is fine.
--
Rich Ulrich

hi Rich,
but, ideally, the sex should be entered in the factor section. right? The only thing is not to make contrasts. correct?


Lijun

[Rich Ulrich]

On Tue, 12 Sep 2023 04:11:04 -0700 (PDT), Lijun Zhao

Post by Lijun Zhao

Post by Rich Ulrich
On Mon, 27 Feb 2017 13:56:11 -0800 (PST), Bruce Weaver

Post by Bruce Weaver

Post by Sushma Dhital
I read that independent categorical variable should be treated as factors, is it true?

Yes, Factors are categorical explanatory variables (e.g., sex, marital status), and Covariates are continuous (or at least quantitative) explanatory variables (e.g., age, body weight).

Of course -- you can code up the dummy variables for
the factors and do the whole analysis of ANOVA with a
regression program. That is what all modern stat-packages
do, internally.
If you want to think of one factor as being in the model as
a logical "covariate" (with 1 or more d.f.), that is fine.
--
Rich Ulrich

hi Rich,
but, ideally, the sex should be entered in the factor section. right?

I don't know why you say 'ideally' -- If you have NO interest in
interactions or means, your output is easier to read if it is a
covariate.

Post by Lijun Zhao
The only thing is not to make contrasts. correct?

? If you don't want contrasts ... I don't follow what you ask.