[R-sig-ME] A question about multicollinear fixed/random factors

[N o s t a l g i a]

Dear Prof. Veríssimo,

Thanks for your prompt reply. I will proceed to analyze the data with 
both days (as fixed) and the meeting (as random) included. Yes, I 
understand the inclusion of session as another random factor and 
by-word random slopes should be considered seriously.

Thanks again,

- Kenjiro Matsuda


On 2022/08/20 19:15, João Veríssimo wrote:
> If I'm understanding this right, I don't think there is a problem at all.
> Mixed-effects models can accommodate fixed effects at different levels 
> and these can coexist with the random effects without any issues. 
> Number of days is simply a 'Level-2' predictor, with a unique value 
> for each meeting.
> 
> (for more complex random-effects structures, you might want to 
> consider the inclusion of session as another random factor and/or of 
> by-word random slopes)
> 
> João
> 
> On 20/08/2022 09:40, N o s t a l g i a wrote:
>> Hi,
>>
>> I am looking at a character variation in Japanese parliamentary 
>> minutes where the same character appears in two forms. In the 
>> parliament, there are a number of different committee meetings 
>> within the same session, and I am looking at 31 sessions over 10 
>> years. The factors I am considering are: upper/lower house 
>> distinction, meetings (meetings within each session, which are 
>> different from session to session), days between 1949/5/20 (when the 
>> first parliament was held) and the meeting, and the word within 
>> which the character appears. Of these, meetings and the words are 
>> random factors, and they have hundreds of levels. The total number 
>> of cases is over one million.
>>
>> The model I am considering is:
>>
>> glmer (character ~ ul + days + (1|word) + (1|meeting), data = 
>> glmmdata.1, family = binomial)
>>
>> And here is my question: Since a given meeting is a unique one not 
>> only in each session but in all the data, there would be a 
>> multicollinear relationship between the days and the meeting, so 
>> that specification of some meeting would necessarily result in a 
>> specific value of days. Is it a problem in GLMM to have such pair of 
>> fixed and random factors? If it is so, is there any ways to avoid 
>> the problem?
>>
>> Thanks in advance,
>>
>> Kenjiro Matsuda
>> Professor in Linguistics
>> Kobe Shoin Women's University
>> Kobe, Japan
>>
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> 
>