As Language Teaching Methods have changed and progressed over time, the role of corrective feedback has also made remarkable progress in the last two decades, partícularly in the 90's.
Concerning the inconsistency and effectiveness of recasts and corrective feedback in general, it has come to be known that problems regarding the inconsistency and ambiguity are due to the lack and unsystematic approaches adopted by the majority of teachers as far as correction is concerned. Thus, in order for corrective feedback to be very effective teachers need to more consistent and Systema tic when correcting faulty utterances because it has been found that teachers sometimes accept ill-formed utterances and some other times they do not.
References