glmer() cluster sample size
Thank you Thierry! That was it... Best, Hedyeh Ahmadi, Ph.D. Statistician Keck School of Medicine Department of Preventive Medicine University of Southern California LinkedIn www.linkedin.com/in/hedyeh-ahmadi<http://www.linkedin.com/in/hedyeh-ahmadi> <http://www.linkedin.com/in/hedyeh-ahmadi><http://www.linkedin.com/in/hedyeh-ahmadi>
From: Thierry Onkelinx <thierry.onkelinx at inbo.be>
Sent: Friday, March 31, 2023 12:42 AM
To: Hedyeh Ahmadi <hedyehah at usc.edu>
Cc: R-mixed models mailing list <r-sig-mixed-models at r-project.org>
Subject: Re: [R-sig-ME] glmer() cluster sample size
Sent: Friday, March 31, 2023 12:42 AM
To: Hedyeh Ahmadi <hedyehah at usc.edu>
Cc: R-mixed models mailing list <r-sig-mixed-models at r-project.org>
Subject: Re: [R-sig-ME] glmer() cluster sample size
It looks like some subjects were present at multiple locations. The number of levels is the number of unique combinations of site and subject. ir. Thierry Onkelinx Statisticus / Statistician Vlaamse Overheid / Government of Flanders INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND FOREST Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance thierry.onkelinx at inbo.be<mailto:thierry.onkelinx at inbo.be> Havenlaan 88 bus 73, 1000 Brussel www.inbo.be<https://urldefense.com/v3/__http://www.inbo.be__;!!LIr3w8kk_Xxm!s82DeZaDffD94Y8Lfu4B6gDYTMqFzNSom9FgEg-ZssQkXtGjbNKvwO63igeiw4Cy1X0ZfzEgwlXuEN8EkBBFomJLhiI$> /////////////////////////////////////////////////////////////////////////////////////////// To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey /////////////////////////////////////////////////////////////////////////////////////////// [https://inbo-website-prd-532750756126.s3-eu-west-1.amazonaws.com/inbologoleeuw_nl.png]<https://urldefense.com/v3/__https://www.inbo.be__;!!LIr3w8kk_Xxm!s82DeZaDffD94Y8Lfu4B6gDYTMqFzNSom9FgEg-ZssQkXtGjbNKvwO63igeiw4Cy1X0ZfzEgwlXuEN8EkBBFcESLUDE$> Op vr 31 mrt 2023 om 01:11 schreef Hedyeh Ahmadi <hedyehah at usc.edu<mailto:hedyehah at usc.edu>>: Hello all, I'm running a glmer() model with 3 levels where individuals are nested within 21 sites and each individual has 1 to 2 repeated measures. My model has the random effect structure (1|site/subjet_id). So I have sample sizes in glmer() output for 3 levels as follows: Site=21 Subject_id:site=9334 Total number of observations=17592 I was wondering how are these sample sizes calculated in R? I was under impression that they are just unique number of site, subject_id, and total number of rows, for complete cases across all my varibles, respectively. This is true for my site and total sample sizes but the subject_id:site sample size is confusing me. Shouldn't this just be the number of unique subject ids? When I look at number rof unique ids, I get 9301 but the glmer() output for subject_id:site is 9334. Thank you in advance for your time. Best, Biostatistician? Keck School of Medicine Department of Preventive Medicine University of Southern California LinkedIn www.linkedin.com/in/hedyeh-ahmadi<https://urldefense.com/v3/__http://www.linkedin.com/in/hedyeh-ahmadi__;!!LIr3w8kk_Xxm!s82DeZaDffD94Y8Lfu4B6gDYTMqFzNSom9FgEg-ZssQkXtGjbNKvwO63igeiw4Cy1X0ZfzEgwlXuEN8EkBBFTiPxn6s$><http://www.linkedin.com/in/hedyeh-ahmadi<https://urldefense.com/v3/__http://www.linkedin.com/in/hedyeh-ahmadi__;!!LIr3w8kk_Xxm!s82DeZaDffD94Y8Lfu4B6gDYTMqFzNSom9FgEg-ZssQkXtGjbNKvwO63igeiw4Cy1X0ZfzEgwlXuEN8EkBBFTiPxn6s$>> [[alternative HTML version deleted]] _______________________________________________ R-sig-mixed-models at r-project.org<mailto:R-sig-mixed-models at r-project.org> mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models<https://urldefense.com/v3/__https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models__;!!LIr3w8kk_Xxm!s82DeZaDffD94Y8Lfu4B6gDYTMqFzNSom9FgEg-ZssQkXtGjbNKvwO63igeiw4Cy1X0ZfzEgwlXuEN8EkBBFyZ4Ap_w$>