abstract = "This paper proposes a novel grammar-guided genetic
programming algorithm for subgroup discovery. This
algorithm, called comprehensible grammar-based
algorithm for subgroup discovery (CGBA-SD), combines
the requirements of discovering comprehensible rules
with the ability to mine expressive and flexible
solutions owing to the use of a context-free grammar.
Each rule is represented as a derivation tree that
shows a solution described using the language denoted
by the grammar. The algorithm includes mechanisms to
adapt the diversity of the population by self-adapting
the probabilities of recombination and mutation. We
compare the approach with existing evolutionary and
classic subgroup discovery algorithms. CGBA-SD appears
to be a very promising algorithm that discovers
comprehensible subgroups and behaves better than other
algorithms as measures by complexity, interest, and
precision indicate. The results obtained were validated
by means of a series of nonparametric tests.",