Standard parton distribution function sets do not have rigorously quantified
uncertainties. In recent years it has become apparent that these uncertainties
play an important role in the interpretation of hadron collider data. In this
paper, using the framework of statistical inference, we illustrate a technique
that can be used to efficiently propagate the uncertainties to new observables,
assess the compatibility of new data with an initial fit, and, in case the
compatibility is good, include the new data in the fit.Comment: 22 pages, 5 figure
