Recent studies of Ion Temperature Gradient (ITG) turbulence using three-dimensional fluid codes (for example [1]) suggest a link between changes in confinement scaling (i.e. Bohm or gyro-Bohm) and the proximity to some form of turbulence threshold. The simulations indicate Bohm scaling when below this threshold and gyro-Bohm scaling when above threshold. Crossing the threshold may result in particle and energy transport switching regimes. Experimentally, global scaling laws typically show elements of both Bohm scaling (in the edge plasma) and gyro-Bohm (in the core plasma). Several experiments (DIII-D [2], TFTR [3] and JET) also show that core turbulence during the H-mode phase is intermittent, or bursting in nature. This suggests that the plasma turbulence may be close to a threshold and that excursions across this threshold result in the intermittent variations in the level and structure (specifically the radial/toroidal correlation lengths) of the turbulent fluctuations. A possible implication of this is that the experimentally measured time-average global transport would appear to scale with a value between pure Bohm and pure gyro-Bohm.