We report a careful finite size scaling study of the metal insulator\ntransition in Anderson's model of localisation. We focus on the estimation of\nthe critical exponent $\\nu$ that describes the divergence of the localisation\nlength. We verify the universality of this critical exponent for three\ndifferent distributions of the random potential: box, normal and Cauchy. Our\nresults for the critical exponent are consistent with the measured values\nobtained in experiments on the dynamical localisation transition in the quantum\nkicked rotor realised in a cold atomic gas.\n