[R-meta] extract pval from robust function

[Martineau, Roger]

Thanks Wolfgang

fitstats(res)[5] worked.

Roger ☺

-----Original Message-----
From: Viechtbauer, Wolfgang (SP) <wolfgang.viechtbauer using maastrichtuniversity.nl> 
Sent: Thursday, March 24, 2022 9:36 AM
To: Martineau, Roger <roger.martineau using AGR.GC.CA>; r-sig-meta-analysis using r-project.org
Subject: RE: [R-meta] extract pval from robust function

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Hi Roger,

Have you tried using str() to figure out the structure and going from there?

Whether ICs are useful when one is using cluster-robust inference methods is an interesting question. I don't see why not. Cluster-robust inference methods are for making inferences about the model coefficients, while ICs are for figuring out what model may be the best (or least bad) approximation to the underlying true data generating mechanism (DGM).

We typically use cluster-robust inference methods when we are worried about the model being misspecified (e.g., not capturing all dependencies). In the present context, this often results from using an overly simplistic V matrix (assuming independent sampling errors or using a roughly approximated V matrix) but could also result from an underspecified random effects structure. In any case, we then suspect that the model is a less than ideal approximation to the DGM, but by comparing several different such misspecified models, we can still see which one(s) are better approximations. In essence, all models are misspecified, so that is an inherent reality we have to accept when using ICs for model selection.

Best,
Wolfgang

>-----Original Message-----
>From: R-sig-meta-analysis 
>[mailto:r-sig-meta-analysis-bounces using r-project.org] On Behalf Of 
>Martineau, Roger
>Sent: Thursday, 24 March, 2022 13:51
>To: r-sig-meta-analysis using r-project.org
>Subject: Re: [R-meta] extract pval from robust function
>
>Hi Wolfgang,
>
>Thanks for your answer, it works.
>
>One more thing, using the dat.konstantopoulos2011 example, I asked for 
>the fitstats of res. I need to extract the AICc value, i.e. 23.3; how can I do it ?
>Also, I assume that those fitstats data are valid using the robust 
>function results; are they ?
>
>> fitstats(res)
>           REML
>logLik:   -7.24
>deviance: 14.48
>AIC:      22.48
>BIC:      30.44
>AICc:     23.30
>
>Thanks in advance,
>
>Roger ☺
>
>-----Original Message-----
>From: Viechtbauer, Wolfgang (SP) 
><wolfgang.viechtbauer using maastrichtuniversity.nl>
>Sent: Thursday, March 24, 2022 8:17 AM
>To: Martineau, Roger <roger.martineau using AGR.GC.CA>; 
>r-sig-meta-analysis using r- project.org
>Subject: RE: [R-meta] extract pval from robust function
>
>Hi Roger,
>
>robust(res, cluster=dat$district)$pval[2]
>>Use str() to find out about the structure of an object, so:
>
>str(robust(res, cluster=dat$district))
>
>Scanning through all that stuff will often lead to the answer.
>
>Best,
>Wolfgang
>
>>-----Original Message-----
>>From: R-sig-meta-analysis
>>[mailto:r-sig-meta-analysis-bounces using r-project.org] On Behalf Of 
>>Martineau, Roger
>>Sent: Thursday, 24 March, 2022 12:58
>>To: r-sig-meta-analysis using r-project.org
>>Subject: [R-meta] extract pval from robust function
>>
>>Dear list members,
>>
>>In this example, the p-value of year in the robust function is 0.5885; 
>>what are the codes to extract that p-value ?
>>
>>dat <- dat.konstantopoulos2011
>>res <- rma.mv(yi ~ year, vi, random = ~ 1 | district/school, data=dat) 
>>robust(res, cluster=dat$district)
>>
>>Thanks in advance.
>>
>>Roger :)