Search found 156 matches

by billb
Thu Oct 08, 2020 12:55 pm
Forum: MLwiN user forum
Topic: Detecting significant results
Replies: 6
Views: 11267

Re: Detecting significant results

Hi Sabine, The estimates from MQL / PQL are quasi-likelihood so you cannot do a standard likelihood-based test to get a P value. You can do an approximate Wald test via the intervals and tests window but bear in mind this assumes normality for the variables so is only an approximation. Hope that hel...
by billb
Tue Jul 28, 2020 12:24 pm
Forum: MLwiN user forum
Topic: Constraining multilevel logistic regression model
Replies: 5
Views: 10521

Re: Constraining multilevel logistic regression model

If you leave it unconstrained then it is simply pointing to the maximum (quasi)likelihood solution being 0 for the variance i.e. there is probably no influence of the hierarchical structure. You could try fitting the model using MCMC to see what estimates that gives,
Bill.
by billb
Tue Jul 28, 2020 12:04 pm
Forum: MLwiN user forum
Topic: Constraining multilevel logistic regression model
Replies: 5
Views: 10521

Re: Constraining multilevel logistic regression model

Dear KW844529, What you are doing doesn't make sense at all as in the logistic regression model, value normally used for the level 1 variance stored in that column is in fact the scaling factor for over/underdispersion and set at 1 for a standard logistic regression with binomial variation. It there...
by billb
Tue Jun 30, 2020 11:19 am
Forum: MLwiN user forum
Topic: Power/Effective Sample Size
Replies: 5
Views: 14064

Re: Power/Effective Sample Size

The effective sample size and Raftery Lewis are completely different diagnostics and in fact a low Raftery Lewis number is good as the diagnostic is a minimum number to run for. In contrast a high ESS is good as it gives an estimate of the equivalent number of independent estimates for the parameter...
by billb
Fri May 15, 2020 8:37 am
Forum: R2MLwiN user forum
Topic: Complex surveys with MI and replicate weights
Replies: 3
Views: 10425

Re: Complex surveys with MI and replicate weights

Dear GKonyarov, Thanks for the post. I have read it a couple of times and although you describe your models I wasn't sure what exactly question you are asking here? Apologies that in lockdown I have been a bit slow to look at the forums and sadly we have lost our colleague Harvey Goldstein whose pap...
by billb
Fri May 15, 2020 8:32 am
Forum: MLwiN user forum
Topic: How to estimate a multi-level multi-process event history model (binary and categorical responses)
Replies: 2
Views: 4046

Re: How to estimate a multi-level multi-process event history model (binary and categorical responses)

Hi Ashley, Thanks for your question. I am a bit rusty on these sorts of models and taking a quick look at the equations window in MLwiN when you try and fit multivariate response models you are restricted to responses being normal, binomial or Poisson. I don't know if this has changed since the slid...
by billb
Fri May 15, 2020 8:20 am
Forum: R2MLwiN user forum
Topic: Pre-post design
Replies: 1
Views: 9921

Re: Pre-post design

Hi Ken, Apologies that this one hasn't been answered after so long. Basically I think R2MLwiN has a very similar syntax to glmer and thus will likely fit the same models. They are using different algorithms so I am not sure which will be the quicker. I suspect estimates for 2 models would be similar...
by billb
Mon Apr 20, 2020 5:39 pm
Forum: MLwiN user forum
Topic: variance function and its uncertainty
Replies: 4
Views: 4671

Re: variance function and its uncertainty

Hi Sun,
Not really as as you say you don't have normality so any use of the SEs would be very approximate. you might consider bootstrapping I guess but easiest with MCMC.
Best wishes,
Bill.
by billb
Thu Apr 02, 2020 3:33 pm
Forum: MLwiN user forum
Topic: variance function and its uncertainty
Replies: 4
Views: 4671

Re: variance function and its uncertainty

Hi Sun, With regard MCMC my suggestion is to look at my MCMC manual where I cover how one works out confidence intervals for derived quantities - here I cover in section 4.7 the difference between 2 schools, 4.8 their ranks with CIs and most relevant for you the ICC/VPC in section 4.9. Here you can ...
by billb
Fri Mar 13, 2020 4:26 pm
Forum: runmlwin user forum
Topic: Jointly test coefficient is 0 across 3 outcomes from trivariate cross-classified model fitted using MCMC
Replies: 1
Views: 3152

Re: Jointly test coefficient is 0 across 3 outcomes from trivariate cross-classified model fitted using MCMC

Hi Rachael,
MCMC is fitting a Bayesian model so the concept of a classical P value is not valid for MCMC estimates - I think we do offer Bayesian P values for all parameters though which basically check what proportion of iterations are positive / negative for a chain.
Best wishes,
Bill.