This study examined the availability and utility of negative feedback provided in the context of task-based adult conversations between native speakers and non-native speakers. Subjects were 10 dyads each consisting of a native English speaker and a college-level student of English as a Second Language. Analysis of conversational interactions involving problem-solving tasks revealed that negative feedback in the form of negotiation and recasts was relatively infrequent in these conditions. Further analysis indicated that provision of negative feedback was highly contingent on the information value of the utterance, as determined by the function that the error utterance served in the overall discourse structure of the conversation. While some indication of immediate and non-immediate incorporation of recast was observed, the rather low incorporation rate coupled with low rates of provision of negative feedback suggest that recasts provided in untutored, task-based settings may not be sufficient to drive interlanguage development toward greater accuracy. It is suggested that activities with predominant meaning focus, but with added focus on form, may be needed to draw learners' attention to form and facilitate interlanguage development. (Contains 35 references.) (MSE)