Revision is one of the fundamental processes of translation. There is a growing number of studies focusing on types of mistranslation and/or revision, which suggests the importance of examining errors and applying due revisions for managing translation quality. However, with some exceptions, little work has been carried out on the establishment of commonly applicable revision categories for translation training, and consequently little revision data have been accumulated. Against this backdrop, this paper presents a quality assessment scheme for English-to-Japanese translations produced by learners. We created a revision typology and a decision tree, through an iterative re-organization of an existing typology, assessing learners’ translations, and hypothesizing the conditions for consistent decision making in identifying revision categories. This paper also reports the characteristics and patterns of revisions applied to university students’ translations and the correlation between the revision types and the learning level.