I'm using an lmer on a set of continuous data. This post helped me a great deal when interpreting results, as I have two conditions and three levels as well, but I've run into a frustrating problem.
My data is from French speakers in two conditions: 1) with an English interviewer and 2) with a French interviewer. They are either intermediate, advanced, or native proficiency.
When the reference level is "Eng/Intermediate," I get different pMCMC values than when the reflevel is "Fr/Intermediate," between the same groups. I starred what should be the p-values for Intermediate vs. Advanced in the French condition as an example. The first set of R output is with group = eng and proficiency = intermediate as the reflevels, and the second is with group = fr and proficiency = intermediate as the reflevels.
Estimate MCMCmean HPD95lower HPD95upper pMCMC Pr(>|t|)
(Intercept) 2254.16 2253.65 2148.11 2362.66 0.0001 0.0000
groupfr 129.93 130.18 81.42 179.85 0.0001 0.0000
proficiencyadvanced -195.87 -195.60 -331.20 -58.28 0.0082 0.0080
proficiencynative -80.76 -80.36 -235.26 70.25 0.2780 0.3241
groupfr:proficiencyadvanced 75.94 75.66 11.75 138.42 **0.0184** 0..0195
groupfr:proficiencynative -58.95 -59.60 -130.00 12.38 0.1006 0.1017
Estimate MCMCmean HPD95lower HPD95upper pMCMC Pr(>|t|)
(Intercept) 2384.10 2384.86 2280.74 2495.84 0.0001 0.0000
groupeng -129.93 -130.61 -180.48 -80.20 0.0001 0.0000
proficiencyadvanced -119.92 -120.64 -257.98 17.45 **0.0812** 0.1051
proficiencynative -139.72 -140.22 -293.25 12.33 0.0708 0.0885
groupeng:proficiencyadvanced -75.94 -74.91 -137.69 -10.48 0.0204 0.0195
groupeng:proficiencynative 58.95 59.77 -11.66 129.56 0.0974 0.1017
Am I misinterpreting the output of pvals.fnc? Thanks in advance for any help.
