===================================================================================
 EPSA paper: Inference for multilevel models when the number of clusters is small.
===================================================================================

.. post:: 2014-06-21
   :category: research

.. previewimage:: randomInter-lme-tcoverr-x2.png

In a recent article published in AJPS it is claimed that Bayesian
estimators have a superior performance in the estimation of the
influence of group-level covariates, especially if the number of
groups/clusters is small. `In the paper presented at
EPSA </research/papers>`__, we show that the problems addressed by
Bayesian techniques can also be adequately addressed by a frequentist
technique, *restricted maximum likelihood*, without the problems
involved in Bayesian estimation, such as the computational cost and the
need to select an appropriate prior.

.. figure:: randomInter-lme-tcoverr-x2.png
   :figwidth: 700px
   :align: center

   Coverage error of Student-\ *t* based confidence intervals of the
   coefficient of a group-level covariate, with different numbers of groups
   and two different estimation methods, *maximum likelihood* and
   *restricted maximum likelihood*.