On asteroid classifications in families

Asteroid classifications are examined, showing that apparent statistical discrepancies exist among all published classifications and discussing the possible causes of that. The asteroids belonging to the families Themis, Eos, Coronis, Maria, Phocaea, Nysa, and Io/Tyche are listed and synoptic views of the first six are given. Reasons for the differences in membership are discussed, including differences in the method for proper elements computation, rejection criterion for the objects to be classified, size of the available data sample, method for family identification, and rejection criterion for family membership. A more extended discussion is given to the last two. It is concluded that only the Themis, Eos, and Coronis families can be considered not controversial.