--- In [email protected], Joseph Coveney <jcoveney@b...> wrote:
> Joseph Wagner wrote:
>
> Thank you for your response. My data is in -wide- format. In order
> to use -ologit- or -gllamm-, does my data necessarily need to be in
> -long- format? I am guessing that either I need to or I have set up
> -ologit- and -gologit- incorrectly since the coefficient and p-value I
> get are quite different. Looking at the table it appears there isn't
> a difference between the two time points and the results I get from
> your programming supports this.
>
>
--------------------------------------------------------------------------------
>
> Yes; the data need to be -reshape-d long in order to use -ologit- or
-gllamm-.
>
> Inspection of the -ordplot- plot leads me to the same conclusion
that you've
> drawn: the scores are essentially the same between the two
observation time
> points. (I'm sorry for my confusion over the relation between
-ordplot- and
> -distplot-. Thanks to Nick for straightening me out on this.)
>
> Ralph B. D'Agostino, Sr., has written on robustness of Student's t
test for
> ordered categorical data--did you get the chance to try -mvrepeat-
or -ttest-
> and compare its results to the others'?
>
> Joseph Coveney
Thanks for your help. -ttest- and -mvrepeat- gave similar results to
each other and to -ologit- in the long data. However, -npt_s-
returned an error and -gllamm- returned "no observations"
I used -ttest- and -mvrepeat- on the wide data and these results:
Ho: mean(hvhlths - f6hlths) = mean(diff) = 0
Ha: mean(diff) < 0 Ha: mean(diff) != 0 Ha: mean(diff) > 0
t = 0.6863 t = 0.6863 t = 0.6863
P < t = 0.7535 P > |t| = 0.4929 P > t = 0.2465
One-way MANOVA for Repeated Measures
dependent variables: hvhlths f6hlths
S=1 M=-.5 N=186.5
Test Value F Num DF Den DF Pr > F
-----------------------------------------------------------
Wilks' Lambda 0.998745 0.471 1 375.0000 0.4929
When I -reshape-d long:
somersd eval hlths, cluster(id)
------------------------------------------------------------
|
eval | Coef. z P>|z| [95% Conf. Interval]
--------+----------------------------------------------------
hlths | -.0088652 -0.35 0.727 -.0586776 .0409471
-------------------------------------------------------------
ologit hlths eval, cluster(id)
hlths | Coef. z P>|z| [95% Conf. Interval]
-------+-----------------------------------------------------
eval | -.030391 -0.35 0.727 -.2007067 .1399247
-------------------------------------------------------------
npt_s hlths, by(eval) strata(id) nodetail
gives: r(198);
gllamm hlths eval, i(id) family(binomial) link(ologit)
gives: no observations
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
