With the rise in research on the role of output in SLA, one occasionally sees the phrase “input versus output” or “the input versus output debate,” or even “the roles of comprehension and production,” in titles of papers1. It may seem obvious to most that output plays some kind of role in SLA. What is not clear to all researchers is the extent of that role, its necessity, or what processes it affects or interacts with. To be sure, few discount a role for input and acquisition is generally characterized in just about any theory as being input dependent in some way (see, e.g., the discussion in Gass, 1997). Indeed, the various chapters in this volume assume the input-dependent nature of acquisition. The question then becomes to what extent acquisition can be characterized as output dependent. Because the field of SLA research has begun to explore roles for both input and output, I find it puzzling to see phrases such as “input vs. output” describing the various positions taken by some scholars.