Letter to the Editor: About the quality and impact of scientific articles.

It is argued that counting the total number of times a scientific article is cited by others, does neither result in a proxy for its cognitive impact nor for its quality. One would have to distinguish at least substitutable and fundamental references. A supposed correlation between peer review assessments and citation counts is conceptually problematic, because peer review includes objective as well as subjective considerations (convictions). With refined methods, however, a differential citation analysis might be able in the future to answer if a given article did or did not have positive cognitive impact on subsequent research.