Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: AW: lincom


From   Nikolaos Pandis <[email protected]>
To   [email protected]
Subject   Re: st: AW: lincom
Date   Thu, 18 Jun 2009 07:53:16 -0700 (PDT)

Dear Martin,

Thank you for the posting. I apologize for being unclear and also because I am asking very basic questions. 

I am not sure I understand the purpose of this command after let's say a linear  regression.

Let's say we have:

xi: regress continvar i.catvar with 3 levels

the regression  table will show levels 2 and 3 and compare them with the reference level 1 of the categorical variable. Why would you run the lincom command. I am not sure I understand its purpose. Would you be able to compare level 2 with level 3 with the lincom command?

Regarding the anova post hoc I meant the following:

If I do a one-way ANOVA like below:

oneway continvar catvar, scheffe

I would get the an F-value and p-value which will be telling me whether there is a sig. difference between any of the category levels, whereas the -scheffe- option will do the "post hoc"- pairwise comparisons between the groups 1&2, 1&3 and 2&3 and tell me which groups are actually different.

Are the objectives of the lincom command similar the  scheffe option in the above examples? Do I have it all wrong? 

Thank you very much.

Nikolaos
--- On Thu, 6/18/09, Martin Weiss <[email protected]> wrote:

> From: Martin Weiss <[email protected]>
> Subject: st: AW: lincom
> To: [email protected]
> Date: Thursday, June 18, 2009, 4:23 PM
> 
> <> 
> 
> What exactly is a "post hoc" test? Apart from that, the
> help file for
> -lincom- does a good job under "Description". What else do
> you want to know
> about the command?
> 
> Note that -lincom- works after any estimation command, so
> the -regress- case
> may not be as special as you think...
> 
> 
> 
> HTH
> Martin
> 
> -----Ursprüngliche Nachricht-----
> Von: [email protected]
> [mailto:[email protected]]
> Im Auftrag von Nikolaos Pandis
> Gesendet: Donnerstag, 18. Juni 2009 14:46
> An: [email protected]
> Betreff: st: lincom
> 
> Hi,
> 
> I would like to ask if you would possibly direct me to a
> site/article ect
> that explains in detail the use and meaning of the -lincom-
> command (after
> -regress-).
> 
> How is this command related (if it is related) with the
> anova post hoc
> tests.
> 
> Thank you very much.
> 
> Nick
> 
> 
>       
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
> 
> 
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
> 


      

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index