One of the basic presumptions of brainstorming is that a focus on generating a large number of ideas enhances both the number of ideas generated and the number of good ideas (original and useful). Prior research has not clearly demonstrated the utility of such a quantity focus in comparison to a condition in which quantity is not emphasized. There have been some comparisons of the impact of quantity and quality focus on the number and quality of ideas, but the results of these comparisons have been mixed. The present study examined brainstorming with four different types of instructions: no specific focus, a quantity goal, a quality goal, or a joint quantity and quality goal. The quantity goal condition was superior to the other three conditions in leading to the generation of more ideas and more good ideas. These findings support Osborn's (1953) assumption that a quantity focus is most beneficial for brainstorming.