.. _method-multilevel_blue-pilot_samples-independent:

"""""""""""
independent
"""""""""""


Independent pilot sampling for groups in multilevel BLUE



.. toctree::
   :hidden:
   :maxdepth: 1



**Specification**

- *Alias:* None

- *Arguments:* None


**Description**



The pilot sample provides initial estimates of group covariances
during the first iteration of the multilevel best linear unbiased
estimator (ML BLUE) sampling approach.  

ML BLUE requires independent samples per group, and this option starts
from independent pilot samples for each of the groups in ML BLUE.
This approach results in a more expensive initialization for the group
covariances than the shared pilot sample approach (the default) and it
may result in lower efficiency in the case where it invests pilot
samples for groups that turn out to be inactive in the subsequent resource
allocations.  Its advantage is simplicity in that group sample increments
simply update the existing group covariances since they were constructed
independently from the beginning.