EN
The purpose of this article is to introduce a taxonomy on whose basis we identify the most common global and local errors made in participants’ essays. At the same time we explain individual steps taken in this systematic procedure. Based on this procedure we gained data that we used to compare the initial and current level of the writing skills of participants in both groups. Subsequently we verified statistically individual hypotheses that deal with the impact of feedback on the development of communicative and linguistic competence in writing in English.