I did a bootstrapping with a mixed model (several variables with interaction and one random variable). I got this result (only partial):
> boot_out
ORDINARY NONPARAMETRIC BOOTSTRAP
Call:
boot(data = a001a1, statistic = bootReg, R = 1000)
Bootstrap Statistics :
original bias std. error
t1* 4.887383e+01 -1.677061e+00 4.362948e-01
t2* 3.066825e+01 1.264024e+00 5.328387e-01
t3* 8.105422e+01 2.368599e+00 6.789091e-01
t4* 1.620562e+02 4.908711e+00 1.779522e+00
......
Now, I wanted to get the confidence intervals for the intercept:
> boot.ci(boot_out,type=c("norm","basic","perc"), index=1)
BOOTSTRAP CONFIDENCE INTERVAL CALCULATIONS
Based on 1000 bootstrap replicates
CALL :
boot.ci(boot.out = boot_out, type = c("norm", "basic",
"perc"), index = 1)
Intervals :
Level Normal Basic Percentile
95% (49.70, 51.41 ) (49.70, 51.41 ) (46.34, 48.05 )
Calculations and Intervals on Original Scale
The bias corrected estimated is:
48.873 -1.677
1 47.196
The problem I have is that the normal and basic CI are outside of the estimate (original and corrected). I just wonder how to cope with that.
Update 1:
Here is a similar questions with a lot of responses.