“…recently asserted that "output may play a number of important roles in language development" and that, in fact, it plays a facilitative role in acquisition~VanPatten, 2004b!, he did not agree with the claim that "using a form in one's output is a direct path to acquisition"~VanPatten, 2004b, p+ 27! and suggested instead, on the basis of current evidence, that acquisition does not appear to be dependent on output~VanPatten, 2004a!+ There are at least two perspectives, however, that ascribe a more fundamental role to output in SLA+ One perspective has suggested that both input and output develop corresponding comprehension and production skills DeKeyser, 1997DeKeyser, , 2001DeKeyser & Sokalski, 1996!+ From a second perspective, the output hypothesis~Swain, 1993hypothesis~Swain, , 1995hypothesis~Swain, , 1998Swain & Lapkin, 1995! holds that although input is essential to SLA, output might also bring about mental processes that both directly and indirectly affect acquisition+ Research motivated by this hypothesis has supported a positive role for output practice in conjunction with input~e+g+, Izumi, 2002;Izumi & Bigelow, 2000;Izumi, Bigelow, Fujiwara, & Fearnow, 1999;Swain, 1995; Swain & Lapkin!+ Following the idea that both input-and output-based instruction can be effective for SLA, many studies have attempted to compare the two under a variety of research designs~Allen, 2000; Collentine, 1998;DeKeyser & Sokalski;Erlam, 2003;Nagata, 1998;Salaberry, 1997!+ Few studies have specifically addressed whether output-based instruction can be as effective as PI when it is matched to PI on all variables other than practice mode+ Recent studies by Benati~2005! and Farley~2001a, 2001b!…”