  A "meta-analysis" is a method for comparison and combination of
nonperturbative parton distribution functions (PDFs) in a nucleon obtained with
heterogeneous procedures and assumptions. Each input parton distribution set is
converted into a "meta-parametrization" based on a common functional form. By
analyzing parameters of the meta-parametrizations from all input PDF ensembles,
a combined PDF ensemble can be produced that has a smaller total number of PDF
member sets than the original ensembles. The meta-parametrizations simplify the
computation of the PDF uncertainty in theoretical predictions and provide an
alternative to the 2010 PDF4LHC convention for combination of PDF
uncertainties. As a practical example, we construct a META ensemble for
computation of QCD observables at the Large Hadron Collider using the
next-to-next-to-leading order PDF sets from CTEQ, MSTW, and NNPDF groups as the
input. The META ensemble includes a central set that reproduces the average of
LHC predictions based on the three input PDF ensembles and Hessian eigenvector
sets for computing the combined PDF+$\alpha_s$ uncertainty at a common QCD
coupling strength of 0.118.
