Hi! I ran the following model in brms and got the following output. However, I would like to code post-hoc interactions. I want to see how different instructional groups performed on spatial and non-spatial uses (idiomaticity) at different test points (pre, post, and delayed posttest). After nesting, I am not sure how to tease out the learning differences across conditions. In fact, I did not nest idiomaticity under test initially but somebody recommended it. I would also like to know when nesting should be necessary. Sorry if my question isn’t clear as I am still new to R and brms.
summary(brm.trans_prior ← brm(Response ~
Condition / TestByIdiom +
(1|Participant) +
(1|ItemNumber),
data=datTrans,
family=‘bernoulli’,
prior=priors,
chains=4, iter=3000, cores=1,
control=list(adapt_delta=0.95)))
#Family: bernoulli
#Links: mu = logit
#Formula: Response ~ Condition/TestByIdiom + (1 | Participant) + (1 | ItemNumber)
#Data: datTrans (Number of observations: 15188)
#Draws: 4 chains, each with iter = 3000; warmup = 1500; thin = 1;
#total post-warmup draws = 6000
#Group-Level Effects:
~ItemNumber (Number of levels: 36)
Estimate Est.Error l-95% CI u-95% CI Rhat Bulk_ESS Tail_ESS
#sd(Intercept) 1.42 0.22 1.05 1.89 1.00 519 740
#~Participant (Number of levels: 79)
Estimate Est.Error l-95% CI u-95% CI Rhat Bulk_ESS Tail_ESS
#sd(Intercept) 0.89 0.05 0.80 0.99 1.00 1018 1935
#Population-Level Effects:
Estimate Est.Error l-95% CI u-95% CI Rhat Bulk_ESS Tail_ESS
#Intercept -0.44 0.24 -0.94 0.02 1.01 444 613
#Condition 0.03 0.07 -0.11 0.16 1.00 693 1342
#Condition:TestByIdiomdelay.spatial 0.41 0.03 0.35 0.46 1.00 4419 4239
#Condition:TestByIdiompost.spatial 0.46 0.03 0.41 0.51 1.00 4768 4846
#Condition:TestByIdiompre.nonspatial 0.02 0.03 -0.04 0.09 1.00 2450 3919
#Condition:TestByIdiomdelay.nonspatial 0.33 0.04 0.25 0.40 1.00 2637 3678
#Condition:TestByIdiompost.nonspatial 0.39 0.04 0.32 0.46 1.00 2342 3520