The intraseasonal oscillations are known to modulate convection and higher-frequency disturbances that propagate through it. These disturbances are of fundamental importance to the oscillation. The larger ones affect the frequency and amplitude of the large-scale oscillation itself. Three different compositing techniques are implemented here, each indicating how and to what extent westward- moving equatorially trapped Rossby waves modulate the ISO. Each composite is based on an index of the eastward-propagating part of Southern Summer ISO OLR activity. The compositing methods are defended, and the physical interpretation of results given.