The role of electron-electron interaction in systems with moderate disorder is poorly understood but it is critically important to understanding quantum transport and the metal-insulator transition. They propose to measure the effect of this interaction for a system in which, for the first time, both the strength of the interaction and the degree of disorder are controllable. The investigation will provide solid experimental data to fill the gap between the theoretically treated regimes of weak and strong disorder, and should also have potential technological impact.