[en] We directly fit the QCD dimensional transmutation parameter, Λ_MS-bar, to experimental data on e⁺e^- jet observables, making use of next-to-leading order (NLO) perturbative calculations. In this procedure there is no need to mention, let alone to arbitrarily vary, the unphysical renormalisation scale μ, and one avoids the ad hoc and potentially meaningless 'theoretical error' associated with standard α_s determinations. PETRA, SLD, and LEP data are considered in the analysis. An attempt is made to estimate the importance of uncalculated next-NLO and higher order perturbative corrections, and power corrections, by studying the scatter in the values of Λ_MS-bar obtained for different observables