“…provided reviews of the research on recasts+ In general, the recast studies demonstrated that implicit feedback of this kind can have a beneficial effect on acquisition, especially when the recasts are more explicit in nature~as in Doughty & Varela, 1998!+ Other studies demonstrated that explicit feedback is of value+ Carroll, Roberge, and Swain~1992!, for example, found that a group that received explicit corrective feedback directed at two complex French noun suffixes~-age and -ment! outperformed a group that received no feedback, although no generalization of learning to nouns not presented during the treatment occurred+ Thus, the recast and explicit feedback studies demonstrated that both types of feedback can be effective+ Table 1 summarizes 11 studies that have compared implicit and explicit corrective feedback+ It is not easy to come to clear conclusions about what these studies reveal due to a number of factors+ First, whereas some of the studies are experimental in nature~e+g+, Carroll, 2001;Carroll & Swain, 1993;Lyster, 2004;Rosa & Leow, 2004!, others are not~e+g+, DeKeyser, 1993Havranek & Cesnik, 2003!, as this second group of researchers investigated corrective feedback through post hoc analyses of normal classroom lessons+ Second, the studies vary in terms of whether they involved laboratory, classroom, or computer-based interaction+ Third, the nature of the treatment activities performed by the learners in these studies differed considerably+ In some cases, the activities involved fairly mechanical exercises~e+g+, Nagata, 1993!, in others they involved communicative tasks~e+g+, Leeman, 2003Muranoi, 2000;Rosa & Leow!, and in others they involved a mixture of the two~DeKeyser!+ Fourth, the treatment also differed in terms of whether it …”