Error message: No random structure specified (POST)

[sharon]

Hi,

I downloaded MLwiN version 2.20 and am trying to go through the practicals in Module 3 of the LEMMA course, but I have a problem with building equations: I follow the instrictions step by step as in the Module 3: Multiple Regression MLwiN Practicals file, but while from the booklet it would appear that the equation builder would automatically add to my equation the error term (ei) once I specify my DV (y), this does not happen in my case. As a consequence, once I try to fit the model, I get the error message No random structure specified (POST). I am sure it is something really silly that I am overlooking, when I first started using MLwiN (with file 3.3 of the training package) I did not have any problem, and the error term would regularly appear in the equations. I tried to use different files, but the problem still occurs. Could anyone please shed light on this for me?

Thank you very much in advance for your much appreciated help

Best

Sharon

[Camster]

Hi Sharon,

To make the error term appear in your equation, you need to add a constant (cons) term first (click on beta0), and you should tick the box corresponding to your level 1 variance.
If you then press the "+" at the bottom that should expand the notation and the error term should appear.

Best wishes

Camille

[sharon]

Thanks a million Camille!

Sharon

[Oak]

I was having the same problem with this.

Thanks Sharon for posting and thanks Camille for solving.

Best wishes

Bob

[sharon]

Hi there,

sorry to be a pain....I followed Camille's advice: I added a cons in Beta 0 and ticked the i [caseid] box. When I press '+' the error term does appear, but it is associated to Beta 0, or so it seems: the ei appears in a separate row, as Beta0i = Beta0 + e 0i. Is that correct? Is there a way to have the error term in the main equation (like it appears in the training material)? I am not sure if I am doing something wrong or it is something to do with the updated version of the program...


Thanks again!
Best

Sharon

[ChrisCharlton]

I suspect that you are viewing the equation with general notation. To switch to simple notation click the "notation" button at the bottom of the equation and untick "general". Once you have done this the equation should match what you are expecting.

[sharon]

Perfect! Thanks Chris! Now I see it the way I like it!

Sha