The stopping forces (a.k.a. stopping powers) for 4 He, 12 C, 16 O, 27 Al and 28 Si ions in alumina (Al 2 O 3 ) have been experimentally determined in the energy range of 40–1250keV/nucleon. Two independent analysis methods based on Simulated Annealing and Bayesian Inference techniques (as implemented in the Hotstop and Data Furnace codes) have been used to extract the continuous stopping curves from sets of backscattering spectra. Bayesian analysis has been found to be very adequate for providing systematic estimations of the confidence level for the results. The results of both methods are reported and compared with other available data.