What Is Connascence and Why Coupling Choices Have a Cost

Connascence is a measure of coupling invented by Meilir Page-Jones in 1996. Two components are connascent when a change in one forces a change in the other. The more components that must change together, the higher the connascence. It gives teams precision beyond tightly coupled versus loosely coupled.

Strength measures how hard the coupling is to change, from static naming to dynamic execution. Locality measures how far apart the coupled elements are. Degree measures how many elements share the relationship. A change that touches ten files has a higher connascence degree than one that touches two.