  We systematically compare an event-by-event heavy-ion collision model to data
from the Large Hadron Collider. Using a general Bayesian method, we probe
multiple model parameters including fundamental quark-gluon plasma properties
such as the specific shear viscosity $\eta/s$, calibrate the model to optimally
reproduce experimental data, and extract quantitative constraints for all
parameters simultaneously. The method is universal and easily extensible to
other data and collision models.
