Search found 156 matches

by billb
Mon Nov 08, 2021 11:44 am
Forum: MLwiN user forum
Topic: Power Analysis: Rules of Thumb
Replies: 1
Views: 4233

Re: Power Analysis: Rules of Thumb

Hi Sabine,
That is really hard to say without knowing what you are hoping to test. Statistical power links to a test and will depend on what that test is and what effect size you are looking for / degree of clustering etc. There should be details in MLPowSim that will help.
Best wishes,
Bill.
by billb
Fri Sep 17, 2021 7:57 am
Forum: MLwiN user forum
Topic: Inclusion of level-one variable increases group level variance in a multilevel negative binomial regression
Replies: 4
Views: 4250

Re: Inclusion of level-one variable increases group level variance in a multilevel negative binomial regression

Hi Liam,
If you register on the online LEMMA course there is stuff about this in unit 7 section 7.2 which is worth a read.
Best wishes,
Bill.
by billb
Wed Sep 01, 2021 1:17 pm
Forum: MLwiN user forum
Topic: Inclusion of level-one variable increases group level variance in a multilevel negative binomial regression
Replies: 4
Views: 4250

Re: Inclusion of level-one variable increases group level variance in a multilevel negative binomial regression

Hi Liam, It is worth noting that for non-Normal multilevel models one has to be careful when interpreting higher level variance terms. The bottom level variance is always fixed by the distributional assumptions made and so when terms are added to the model that fixed variance would normally reduce a...
by billb
Thu Jul 29, 2021 8:08 am
Forum: MLwiN user forum
Topic: Is it a repeated measurements multilevel modeling?
Replies: 7
Views: 6621

Re: Is it a repeated measurements multilevel modeling?

Hi Hakimeh, The challenge you have is so much missing data. For any 1 place lets say that 2 people say it is beautiful and 1 picturesque out of 100 people. What you don't know is the opinions of the other 97 as you only ask them to choose 'an example' so they may all think the place in question is b...
by billb
Wed Jul 28, 2021 7:40 am
Forum: MLwiN user forum
Topic: Is it a repeated measurements multilevel modeling?
Replies: 7
Views: 6621

Re: Is it a repeated measurements multilevel modeling?

Hi Nasirhakimeh, This is quite unusual data and your question is only a little about multilevel modelling so I'll give a brief answer of what I might do and then leave to see if others have ideas. So perhaps a straightforward thing to do is to consider each of the 6 types separately e.g. here are a ...
by billb
Tue Jul 27, 2021 4:31 pm
Forum: MLwiN user forum
Topic: Is it a repeated measurements multilevel modeling?
Replies: 7
Views: 6621

Re: Is it a repeated measurements multilevel modeling?

HI Nasirihakimeh, Apologies that I don't fully follow your structure. Do you have people's views nested within places or places nested within people's views? I think the main thing is with only 6 places you are probably looking at fitting fixed effects for these as they are probably important rather...
by billb
Wed May 19, 2021 12:31 pm
Forum: MLwiN user forum
Topic: Level identification for repeated measures
Replies: 1
Views: 12360

Re: Level identification for repeated measures

Hi Josip, You appear to have a 4 level structure but in practice you would fit this as 3-levels with school just included as fixed effect dummies as you only have 4 schools. I am not sure I understand your 2nd question but fitting it as 3 levels would give you variances for the 3 levels so you could...
by billb
Fri Mar 19, 2021 10:04 am
Forum: runmlwin user forum
Topic: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?
Replies: 4
Views: 11047

Re: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?

So 0.06 would be 1 significant figure (number of digits required after leading 0s) so plug that in and see what it says.
Best wishes,
Bill.
by billb
Fri Mar 19, 2021 8:39 am
Forum: runmlwin user forum
Topic: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?
Replies: 4
Views: 11047

Re: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?

P.S. As you say the Brooks Draper diagnostic is how long is required to be confident to quote your estimate as in this case 0.064 rather than say 0.065 or 0.063 which given your effect is non-significant anyway i.e. the SD here is 0.321 and 95% CI is -0.532 to 0.713 might not be really that importan...
by billb
Fri Mar 19, 2021 8:36 am
Forum: runmlwin user forum
Topic: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?
Replies: 4
Views: 11047

Re: Brooks-Drapers diagnostic says 1,03e+7, do I need to rerun the model with 10 300 000 iterations?

Morning Manuel, The purpose of thinning is largely just to make things feasible due to memory constraints etc. so ideally we wouldn't thin at all but clearly the computer then has to store a lot of numbers. As you rightly say we use running totals for ALL iterations to construct the point estimate a...