Divergence measures based on two entropy families are studied. One fam
ily contains the entropies of degree alpha and the second family embod
ies the entropies of order alpha. The latter entropies are also known
as the Renyi entropies. Both types of divergence measures yield effect
ive quality functions for guiding the growth and optimization of feedf
orward neural networks built of linear threshold units. These function
s are of particular value in the multi-category case. Important proper
ties of these quality functions include their convexity on the domain
of optimization and their greediness to split internal representations
. As a consequence of these properties. these quality functions result
in compact neural networks with good generalization properties. The s
uitability of some divergence measures to serve as a quality function
is verified by a benchmark study. The divergence measures discussed in
this paper are of great importance for the held of constructive learn
ing.