Quantifying the Effectiveness of Mutant Sets

To reduce the cost of mutation testing, researchers have sought to find minimal mutant sets. As an optimization problem, mutant set minimization is defined by two parameters: the objective function that we must optimize; and the constraint under which the optimization is carried out. Whereas the objective function of this optimization problem is clear (minimizing the cardinality of the mutant set), the constraint under which this optimization is attempted has not been clearly articulated in the literature. In this paper, we propose a formal definition of this constraint and discuss in what sense, and to what extent, published algorithms of mutant set minimization comply with this constraint.