[R-meta] rma.mv-When a higher level can't be modeled because of one row

-----Original Message-----
From: Farzad Keyhan [mailto:f.keyhaniha at gmail.com]
Sent: Monday, 08 November, 2021 16:22
To: Viechtbauer, Wolfgang (SP)
Cc: R meta
Subject: Re: rma.mv-When a higher level can't be modeled because of one row

Thanks Wolfgang.

Yes, this is just the data structure. Focusing on the "making
[measure] nested within study" part of your suggestion, you mean in
row # 3, I recode the "measure" value of 1 to 2, or even delete row #
3 altogether, or "~1 | measure/study/outcome" by default will take
care of making "measure" nested in study?

Thank you,
Fred

On Mon, Nov 8, 2021 at 4:13 AM Viechtbauer, Wolfgang (SP)
<wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:

Dear Fred,

I would consider using measure as a fixed effect or making it nested within

study (or within outcome). But none of this might really be appropriate for a
dataset this small (but I assume this was just constructed for illustrating your
question).

Best,
Wolfgang

-----Original Message-----
From: Farzad Keyhan [mailto:f.keyhaniha at gmail.com]
Sent: Friday, 05 November, 2021 2:59
To: R meta
Cc: Viechtbauer, Wolfgang (SP)
Subject: Re: rma.mv-When a higher level can't be modeled because of one row

For clarity, by a solution, I mean how can I account for the
heterogeneity in true effects attributable to "measure", while
"measure" is neither a perfect candidate for being the nestor of
study:

random = ~1 | measure/study/outcome

nor a perfect candidate for being crossed with study:

random = list(~1 | study/outcome, ~1|measure)

Thank you,
Fred

On Thu, Nov 4, 2021 at 2:26 PM Farzad Keyhan <f.keyhaniha at gmail.com> wrote:

Dear Experts,

In my toy data below, if in row # 3, "measure" was 2 (instead of 1),
then, I could take "measure" as a level higher than study:

random = ~1 | measure/study/outcome

But right now, because in study 2 (rows # 3 and 4) "measure" can vary,
"measure" can't be considered a level higher than study.

On the other hand, because "measure" varies only in one study, I can't
take "measure" as a crossed random-effect either.

I was wondering what solutions the expert list members might have for
this situation?

Thanks,
Fred

   measure       row   study   outcome
   1             1     1       1
   1             2     1       2
#  1             3     2       1 <--- measure on this row
   2             4     2       1
   1             5     3       1
   1             6     3       2