Qualitative journal evaluation cumulates content descriptions of single articles. Articles are either represented by author–generated keywords, professionally indexed subject headings, automatically extracted terms or, as recently introduced, by reader–generated tags as used in social bookmarking systems. The study presented here shows that different types of keywords each reflect a different perspective on documents and that tags can be used in journal evaluation to represent a reader–specific view. After providing a broad theoretical background and literature review, methods for extensive automatic term cleaning and calculation of term overlaps are introduced. The efficiency of tags and other metadata for journal content description is illustrated for one particular journal.