Effects of software changes on module cohesion

Program slices are used to model module cohesion. For the authors purposes, a slice is a projection of program text that includes only the data tokens relevant to one output. The authors define six cohesion metrics in terms of these slices, and evaluate the effects of classes of module changes on these metrics. They find that the effects on cohesion metrics are notably more predictable when the changes result from adding code rather than from moving code