What reviewers call a Long Method is a length: A pre-registered test of coupling divergence as a god-unit signal, and what it settled instead

Abstract

A companion study found that a complexity outlier rule shows where complexity concentrates but cannot tell a god unit from a complex algorithm. This paper pre-registered a test of one way to tell them apart: weight a unit's complexity by its coupling divergence, the data it hands on minus the data it receives, so that a leaf is set aside. Coupling was measured by resolving every call in 520 MLCQ repositories, 500 fresh Java repositories and 73 Qualitas Corpus systems. The claim fails: the primary, the pooled MCC of the weighted form minus complexity alone against MLCQ's human Blob, is -0.041 [-0.130, +0.054], no difference resolved and underpowered, and the resolved readings go against it. What the data settle is at method level. What MLCQ's reviewers call a Long Method is an absolute length: a constant of 26 lines or more, chosen on the explore half, reaches MCC 0.777 on the confirm half, +0.080 [+0.016, +0.145] over the best per-repository form; every reviewer with ten or more positives, on their non-leaf reviews, has a best cutoff between 17 and 34 lines; and nothing measured inside a method, its calls, variables, data flow or the cost of cutting it, refines the constant. The constant is a limit of human reading. The next form of the construct is the cost of bringing a long method under it, which is where the construct meets architecture.