[en] The empirical scaling law used to support the projected ITER performance [1, 2] in analysed to determine the control parameters that must be considered in gyrokinetic simulations. The results of such an analysis are contradictory and do not appear to fit with present evidence from gyrokinetic simulations. Analysing the dependence of the correlation length on the ρ_* parameter, we show that local values of the correlation length are governed by the shearing effect of the corrugation patterns, but that coarse graining this value, in time, radially or poloidally does not allow one to recover this match. A comparison to the scaling law must then rely on the scaling properties of the Probability Density Function of the correlation length that is found to exhibit heavy tails with algebraic decay