(The JET Collaboration)Within five different approaches to parton propagation and energy loss in dense matter, a phenomenological study of experimental data on suppression of large pT single inclusive hadrons in heavy-ion collisions at both RHIC and LHC was carried out. The evolution of bulk medium used in the study for parton propagation was given by 2+1D or 3+1D hydrodynamic models which are also constrained by experimental data on bulk hadron spectra. Values for the jet transport parameterq at the center of the most central heavy-ion collisions are extracted or calculated within each model, with parameters for the medium properties that are constrained by experimental data on the hadron suppression factor RAA. For a quark with initial energy of 10 GeV we find that q ≈ 1.2 ± 0.3 GeV 2 /fm at an initial time τ0 = 0.6 fm/c in Au+Au collisions at √ s = 200 GeV/n andq ≈ 1.9 ± 0.7 GeV 2 /fm in Pb+Pb collisions at √ s = 2.76 TeV/n. Compared to earlier studies, these represent significant convergence on values of the extracted jet transport parameter, reflecting recent advances in theory and the availability of new experiment data from the LHC.