Use when grading or loosening the coupling between two pieces of code, or judging how cohesive a module is. Triggers on connascence, coupling vs cohesion, 'too tightly coupled', decouple/loosen, the coupling ladder (content/common/control/stamp/data), the cohesion ladder, Law of Demeter / train wrecks like a.b().c(), positional vs named parameters, or reviewing a module boundary for coupling strength — even when the user doesn't say 'connascence' and only says 'tightly coupled'.
Use when grading or loosening the coupling between two pieces of code, or judging how cohesive a module is. Triggers on connascence, coupling vs cohesion, 'too tightly coupled', decouple/loosen, the coupling ladder (content/common/control/stamp/data), the cohesion ladder, Law of Demeter / train wrecks like a.b().c(), positional vs named parameters, or reviewing a module boundary for coupling strength — even when the user doesn't say 'connascence' and only says 'tightly coupled'.
Connascence: a Precise Coupling Vocabulary
Grade a seam by naming its worst coupling and its strongest connascence, then weaken or localize it — "tight/loose" is unactionable.
Essentials
Name the connascence, don't say "tight" - classify the form and rate strength/locality/degree, see references/connascence.md
Two moves: weaken and localize - rule of degree (strong→weak forms) and rule of locality (distance→weakness), see references/connascence.md
Push every seam down the coupling ladder - content→common→control→stamp→data, worst to best, see references/coupling-ladder.md
Aim for functional cohesion - one job per module; temporal cohesion is the package-by-layer trap, see references/cohesion-ladder.md
Don't reach through strangers - Law of Demeter as the call-site detector for content coupling, see references/law-of-demeter.md
Gotchas
"Tightly coupled" is not actionable — name the connascence form and the coupling rung, then you know the fix.
Strong connascence is fine inside one module; it's only a problem across a boundary (rule of locality).
Control coupling hides as configuration — a behavior flag passed into a shared function recouples its callers; split into two functions.
Law of Demeter is a heuristic, not a law — fluent builders and pure data pipelines are deliberate exceptions; it targets reaching through a stranger to depend on or mutate its internals.
Coupling and cohesion trade off — splitting a module to "loosen coupling" can shred its cohesion; grade both before cutting.
Example
SEAM a billing function reaches into an Order's private `total` field
GRADE content coupling (reaches internals) + connascence of meaning across a boundary
FIX Order exposes a neutral `amountDue()` value (rule of degree → data coupling);
billing reads the value — agreement is now named, local, and weak
Progressive Disclosure
Read references/connascence.md - Load when classifying a coupling (static/dynamic forms, strength/locality/degree, the two rules)
