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Hello, I set up a 2 level ordinal logistic model in MLwiN and then moved things into Realcom Impute. It did produce imputed datasets, but at the end of the prompt screen I saw the following error messages. I was just wondering: to what extent should I care about these messages, or are they ignorable?

Thanks for that Chris, I've been setting it up again and it seems to work, but occasionally take another turn and start freezing up again. I'll see how the next few models go and decide if there's something going wrong with the pasting of data, or if MLwiN just doesn't like me!

Hi folks, I've been working on logistic regression models with about 4,000 pupils in 40 schools, when I go to add a new term I get the pop up rmatrix_list already allocated followed by another popup saying rmatrix_list already allocated(ADDT) and I can't add any terms to the models. Has anyone any i...

Hello Nicky, I'm not 100% what you mean by beta and b here. Have you been using SPSS previously? In SPSS the beta column in the output refers to the standardised coefficients. However in MLwiN, the beta values in the output are the equivalent on the b's in SPSS, they are unstandardised coefficients....

Thanks very much for that Lydia, I suppose by the time I get the models built up I don't need the easiet interpretable reference category, and as the largest will shrink the se's I assume that makes quadrature easier......I have a vague notion that's true from something I was told long ago, but I ha...

Hi, By ordering the categories, I mean changing the reference category, which you mentioned might help, I usually plump for the largest nominal category or the bottom of an ordinal, might the mid point of an ordinal make a difference to estimation? I tried quantiles and then after reading here I tri...

Hi folks, How can you calculate a Wald test by hand/calculator for more than one parameter? I'm not working in MLwiN and don't have the equivalent 'intervals and tests' window figured out. Just in case it's different depending on which combination; I'm interested in testing the addition of random sl...

Thanks very much for this Lydia, it is very helpful. I'm usually not too worried about aiding interpretation of intercepts. I work mostly with discrete data and look for relative differences, controlling for whatever variables and the probabilities from models tend not to interest me themselves. I h...

Hello all, I was wondering about grand mean centreing variable for Multi level models, specifically I'd be interested in answers for the following questions; What are the advantages of using mean centred variables in models (or what are the main advantages)? Do the same advantages apply when using d...