The present chapter explores to what extent methods of writing process analysis can be fruitfully applied to learner corpus data. An analysis of 598 instances of revision in learner data shows that the majority is of a conceptual nature, i.e. involves changes of content. Formal revisions, i.e. revisions demanded by the target language system and thus particularly indicative of the state of the interlanguage system, come second. Within this group, grammatical, lexical and orthographic/typo revisions are far more frequent than revisions that concern questions of idiomaticity or textual cohesion and coherence. This is interpreted as a lack of awareness of the latter aspects on the part of the learner possibly due to a lesser prominence in the EFL curriculum. In addition, it is found that in more than three quarters of all cases of formal revisions, the text is improved. It follows that the quality of the final product may mask problem areas of the learner that only become apparent if we take the writing process into consideration.