Modelled on recent works on reformulation, a correction strategy for foreign writing (Adams, 2003; Sachs and Polio, 2007; Swain and Lapkin, 2002 inter alia), we carried out a pilot study with two 16-year-old Spanish students of English. Unlike previous works, (i) a second correction strategy, self-correction, was used and (ii) the study was carried out within classroom limitations. These new variables respond to the twofold objective of comparing both strategies in terms of their effect on language learning and of their validity for classroom use. Results seem to indicate that reformulation is more effective on error correction while self-correction appears to be less effective but more valid for the classroom context. It was also found that with both correction strategies errors beyond sentence level remained unnoticed. In light of the results, some variations to adapt these strategies to the classroom as well as some lines for future research are suggested.