Problems adopting metrics from other disciplines

In this paper, we argue that metrics validation approaches used in software engineering are problematic. In particular, theoretical validation is not rigorous enough to detect invalid metrics and empirical validation has no mechanism for making any final decisions about the validity of metrics. In addition, we argue that cohesion and information-theoretic metrics are problematic if they are based on mathematical graphs which do not consider program semantics. We conclude that we should not adopt metrics from other disciplines if we cannot validate them properly. We propose the use of the representation condition as a means to demonstrate metrics that are not valid. We also believe that design metrics must make sense to software designers or, even if they are valid, they will not be used.