Squeeziness: An information theoretic measure for avoiding fault masking

Fault masking can reduce the effectiveness of a test suite. We propose an information theoretic measure, Squeeziness, as the theoretical basis for avoiding fault masking. We begin by explaining fault masking and the relationship between collisions and fault masking. We then define Squeeziness and demonstrate by experiment that there is a strong correlation between Squeeziness and the likelihood of collisions. We conclude with comments on how Squeeziness could be the foundation for generating test suites that minimise the likelihood of fault masking.

► Relate fault masking to information flow in software. ► Define Squeeziness as loss of information due to execution of a program or path. ► Define a special case of Squeeziness that produce counting metrics on paths. ► Show that the Squeeziness and Domain to Range Ratio produce inconsistent orderings on execution paths. ► Experiments showing correlation between Squeeziness and form of fault masking.