Residuals and Predictions

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lmc
Posts: 4
Joined: Fri Nov 13, 2009 2:17 pm

Residuals and Predictions

Post by lmc »

I have produced a two level model in MLwiN and I have got predictions of this model. I am trying to verify that the predictions are correct by calculating them myself using the coefficients that have been estimated and the level one and level two residuals. I am unsure however to determine what the level one and level two residuals are and I was wondering if anyone could help me please. I would really appreciate any help anyone could give me. Thanks
Lydia
Posts: 26
Joined: Tue Oct 13, 2009 2:55 pm

Re: Residuals and Predictions

Post by Lydia »

You can calculate residuals via Model -> Residuals. Chapter 3 of the User's Guide, which is available on the CMM website http://www.cmm.bristol.ac.uk/MLwiN/down ... uals.shtml gives details of how to do this. Alternatively, if you are feeling brave, and want to really test the software :), you could check out the audio presentation about residuals on the CMM website http://www.cmm.bristol.ac.uk/learning-t ... duals.html which gives formulae to calculate residuals for yourself!
lmc
Posts: 4
Joined: Fri Nov 13, 2009 2:17 pm

Re: Residuals and Predictions

Post by lmc »

Thanks very much for your reply. I have gotten the calculated residuals for level one and level two by specifying each of these levels in the residuals window. However, when I used these residuals with the equation of the model that I have produced in MLwiN and the coefficients calculated, I do not obtain the same prediction as MLwiN. I was wondering if you know why this would be and how MLwiN calculates the predictions.

I also looked at the presentation that was suggested and found that it uses the predictions to determine the residuals, whereas my aim is to determine how MLwiN calculates the predicted values. Thanks again for you reply. Any help you could give me with this would be really appreciated.
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