We have studied experimentally single-article (small angle) and electr
on-electron scatterings in coupled double-quantum well systems. These
scattering rates were determined by analysis of the resistance resonan
ce (RR) effect in the in-plane magnetic field. We have demonstrated th
at the values for single-particle, scattering rate are in fair agreeme
nt with Shubnikov-de Haas data, and that electron-electron scattering
rates are consistent with theoretical calculations.