[en] We demonstrate two distinctive effects of strain-induced island-island interaction on island size and spatial distribution during coarsening of 2D islands. When coarsening proceeds via only mass transport between islands, the interaction broadens the island size distribution, leading to a power-law dependence of island size uniformity on island number density. When coarsening proceeds via island migration in addition to mass transport between islands, the interaction can effectively direct island motion through island edge diffusion, leading to self-organized formation of a regular array of islands with both uniform size and spacing