  In a previous article (Rahman, Guns, Rousseau, and Engels, 2015) we described
several approaches to determine the cognitive distance between two units. One
of these approaches was based on what we called barycenters in N dimensions.
The present note corrects this terminology and introduces the more adequate
term 'similarity-adapted publication vectors'. Furthermore, we correct an error
in normalization and explain the importance of scale invariance in determining
cognitive distance. We also consider weighted cosine similarity as an
alternative approach to determine cognitive (dis)similarity. Overall, we find
that the three approaches (distance between barycenters, distance between
similarity-adapted publication vectors, and weighted cosine similarity) yield
very similar results.
