Dear list,
I am running a lmer model and have a question.
When ever i put a factor (Mag) in my model it lowers the AIC of the model,
however the intercept is the only value with significant p-value. I have
looked at the coefficients and the standard error and something jumps out at me.
Estimate Std. Error z value Pr(>|z|)
(Intercept) -1.35778 0.30917 -4.392 1.12e-05 ***
MagNew -15.76939 1255.06372 -0.013 0.990
MagOld 0.14250 0.25246 0.564 0.572
MagNew relates to a categorical factor (Mag) that has 3 levels of which New is
one and Old is another ( The third is not displayed).
It appears MagNew has a huge Std.Error, what could cause this?
When i do str(Mag) you will see that New is relatively rare (29 out of 871) i
presume it is this that is raising the Std.Error value. however i am not sure
why this is causing the intercept to have a highly significant p value .
Furthermore how do i interpret it, I am using AIC values as my basis of model
selection and i am unsure if this really is the most likely model or not?
Thanks
Sam
[1] Old Old Old Old Old Old Old Old Old Old Old
[12] Old Old Old Old Old Old Old Old Old Old Old
[23] Old Old Old Mid Old Old Old Mid Old Old Old
[34] Old Old Old Old Mid Old Old Old Old Old Old
[45] Mid Mid Mid Old Old Old Mid Mid Mid Mid Old
[56] Old Old Old Old Old Old Old Old Old Old Old
[67] Old Old Old Old Old Old Old Old Old Old Old
[78] Old Old Old Old Old Old Old Old Old Old Old
[89] Old Old Old Old Old Old Old Old Old Old Old
[100] Old Old Old Old Old Old Old Old Old New New
[111] Old Old Old Old Old Old Old Old Old Old Mid
[122] Mid Mid Mid Mid Old Old Old Old Mid Mid Mid
[133] Mid Mid Mid Mid Mid Mid Mid Mid Mid
Mid Mid
[144] Mid Mid Mid Mid Old Old Old Mid Mid Mid
Mid
[155] Mid Mid Mid Mid Mid Mid Mid Old Old Old
Old
[166] Old Old Old Mid Mid Mid Mid Mid Mid Mid
Mid
[177] Mid Mid Mid Mid Mid Mid Mid Mid Mid
Old Mid
[188] Mid Mid Mid Mid Old Mid Mid Mid Mid Mid
Mid
[199] Mid Mid Old Old Old Old Old Old Old Old Old
[210] Old Old Old Old Old Old Old Old Old Old Old
[221] Old Old Old Old Old Old Old Old Old Old Old
[232] Old Old Old Old Old Old Old Old Old Old Old
[243] Old Old Old Old Old Old Old Old Old Old Old
[254] Old Old Old Old Old Old Old Old Old Old Old
[265] Old Old Old Old Old Old Old Old Old Old Old
[276] Old Old Old Old Old Old Old Old Old Old Old
[287] Old Old Old Old Old Old Old Old Old Old Old
[298] Old Old Old Old Old Old Old Old Old Old Old
[309] Old Old Old Old Old Old Old Old Old Old Old
[320] Old Old Old Old Old Old Old Old Old Old Old
[331] Old Old Old Old Old Old Old Old Old Old Mid
[342] Old Old Old Old Old Old Old New New New New
[353] New New New New New Old Old Old Old Old Old
[364] Old New Old Old Old Old Old Old Old Old Old
[375] Old Old Old Old Old Old Old Old Old Old Old
[386] Old Old Old Old Old Old Old Old Mid Mid Mid
[397] Mid Mid Mid Old Old Mid Old Old Mid Mid Mid
[408] Mid Mid Mid Mid Mid Mid Mid Mid Mid
Mid Mid
[419] Old Old Old Old Mid Mid Mid Mid Mid Old Mid
[430] Mid Mid Mid Mid Mid Mid Mid Mid Mid
Mid Mid
[441] Mid Mid Mid Mid Mid Mid Old Old Old Old Old
[452] Old Old Old Old Old Old Old Mid Mid Old Old
[463] Mid Mid Old Old Mid Mid Mid Mid Mid Old
Mid
[474] Mid Mid Old Mid Old Old Old Old Old Old Old
[485] Mid Mid Mid Mid Mid Mid Mid Mid Mid
Mid Old
[496] Old Old Old Old Old Old Mid Old Mid Old Old
[507] Old Old Old Old Old Old Old Old Old Old Old
[518] Mid Mid Mid Mid Old Mid Old Mid Old Mid
Mid
[529] Old Old Mid Mid Mid Mid Mid Mid Old Mid
Mid
[540] Mid Mid Mid Mid Mid Mid Old Old Old Old Mid
[551] Mid Mid Old Old Mid Mid Old Mid Old Old Old
[562] Old Mid Old Old Old Mid Old Old Old Old Mid
[573] Mid Mid Old Old Mid Mid Mid Mid Old Old Old
[584] Mid Old Old Old Old Old Old Mid Mid Mid Old
[595] Mid Mid Mid Old Old New Mid Mid Old Mid Mid
[606] Mid Old Mid Old Old Mid Mid Mid Mid Mid
Old
[617] Mid Old Old Old Old Old Old Old Old Old Old
[628] Old Old Mid Old Old Old Old Old Old Old Old
[639] Old Old Old Old Old Old Old Old Old Old New
[650] Old Mid Old Old Old Old Old Old Old Old Old
[661] Old Old Old Old Old Old Old Old Old Old Old
[672] Old Old New Old Old Old Old Old Old Old Old
[683] New Old Old Old Old Old Old Old Old Old Old
[694] Old Old Old Old Old Old Old Old Old Old Old
[705] Old Old Old New Old Old New Old Old Old Old
[716] New New New New New Old Old Old New Old Old
[727] Old Old Old Old Old Old Mid Old Old Old New
[738] Old Old Old Old Old Old Old Old Old Old Old
[749] Old Old Old Old Old Old Old Old Old Old Old
[760] New Old Old Old Old Old Old Old Old Old New
[771] Old Old Old Old Old Old Mid Old Old New Old
[782] Old Old Old Old Old Old Old Old Old Old Old
[793] Old Old Old Old Old Old Old Old Old Old Old
[804] Old Old Old Old Old Old Old Old Old Old Old
[815] Old Old Old Old Old Old Old Old Old Old Old
[826] Old Old Old Old Old Old Old Old Old Old Old
[837] Old Old Old Old Old Old Old Old Old Old Old
[848] Old Old Old Old Old Old Old Old Old Old Old
[859] Old Old Old Old Old Old Mid Mid Old Old Old
[870] Old Old
Levels: Mid New Old
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