An experimental methodology is developed to investigate the simultaneous axial and radial mixing of particles in a hoop mixer. This involves following the migration of a colored tracer, with flow properties identical to that of the bulk using tracer detection by image analysis. The particle transitions from all initial tracer positions inside the mixer are calculated and the experimental conditions are established which improve the homogeneity of the mixture. Finally, a Markov chain model is derived which gives a good representation of the experimental data.