Cognitive Scaffold

Preparing your thinking workspace

arrow_back_ios_new
MENTAL MODEL · M0037

Kernighan's Law

Kernighan's Law
BusinessmediumManagement
Included
account_tree

Version 1.0.0 · Updated 2026-07-30

CORE DEFINITION

A programming aphorism attributed to Brian Kernighan says debugging is twice as hard as writing code, warning that excessively clever code makes debugging difficult. “Twice” is rhetorical, not a measured ratio valid for every program or a prescription to reserve half one’s intelligence.

SCAFFOLDING EFFECT

psychology

Reduce cognitive load

Evaluate the later costs of understanding, diagnosing, and changing an implementation. Prefer code the team can explain and test; document and measure complexity needed for performance.

anchor

Anchor fast decisions

Debugging reconstructs actual execution and its divergence from expectations. Complex control flow, hidden state, and lost context add cognitive burden. Clear structure can help, but no fixed multiplier determines debugging cost.

MINIMUM ACTION

In progress 0/3

Practice this model in one real situation:

Check to track your progress (stored locally)
Learning progress0%
account_treeGenealogyexpand_more
menu_bookReferencesexpand_more

Source support: Explicit

RELATED MODELS

Related model

Wirth's Law

Wirth's law is an adage on computer performance which states that software is getting slower more rapidly than hardware is becoming faster.

arrow_forwardRelated model

Gall's Law

Gall’s law is a system-design rule of thumb: make a simple system work, then evolve its complexity.

arrow_forwardRelated model

Innovation Tokens

Any team or project has limited energy and fault tolerance; assume you only have 3 'innovation tokens'.

arrow_forward