how to run a 3 level multilevel model ?

[Romuald Landry]

hello
I wish to make a multi-level analysis with data classified at three levels, namely
student class region
in the empty model should I specify the three variables that allow me to distinguish each level of analysis?

When I do so, the model does not run

my commande mixed

Scoremoyengeneral || ID_STRATE :|| ID_ECOLE :|| ID_ELEVE :
Thank

[Joseph Coveney]

How many observations do you have per student? How many regions to you have?

If you have many observations per student, and only a relative few regions, then maybe start with

mixed Scoremoyengeneral i.ID_STRATE || ID_ECOLE: || ID_ELEVE:

and then go from that.

[Carlo Lazzaro]

Romuald:
as a general rule, whenever Stata warns about convergence issues concerning an MLE-supported statistical analysis, it is wise to start it all over again from a more parsimonius model, adding predictors/level one at time and see where Stata starts to gasp.

[Romuald Landry]

How many observations do you have per student? How many regions to you have?

If you have many observations per student, and only a relative few regions, then maybe start with

mixed Scoremoyengeneral i.ID_STRATE || ID_ECOLE: || ID_ELEVE:

and then go from that.

I have 3817 students
6 regions
266 schools

I tried the code you proposed
but it goes on forever
here is a screenshot

[Joseph Coveney]

I have 3817 students
6 regions
266 schools

I tried the code you proposed
but it goes on forever

My question was: how many observations do you have per student?

I noticed that you don't have any time variable in your model, which I would expect unless you have only one observation per student. And if you have only one observation per student, then it will go on forever. In that case, try

mixed Scoremoyengeneral i.ID_STRATE || ID_ECOLE:

(Although it might be feasible to treat region as random, six regions is somewhat few.)

[Romuald Landry]

indeed I have only one observation per student
data were collected over a single year (so no time variable)
the command you suggested works

How can we currently get the percentage of variation at the school, class and regional level?
Since it is in the empty model that I have to obtain these variations?

I find that school explains 63% of the variations in academic performance,
I couldn't find the percentage explained by the class and the students.