Root Cause Analysis

A stated number pulls subsequent estimates toward it, regardless of relevance.

Analyzing an incident on the assumption everyone involved made a reasonable decision given what they knew at the time.

Living bone is continuously resorbed and rebuilt, which is why fractures heal and why healing runs in stages.

The hypothesis that visible disorder invites serious crime, and the long dispute over whether the evidence supports it.

Imitating the visible form of a practice while the mechanism that made it work is absent.

The algorithm deciding which declaration wins when several apply to the same element.

Do not remove something whose purpose you cannot explain.

Two things moving together is evidence for a causal link but never proof of one, or of its direction.

Time-based scheduling of recurring jobs, and the reasons scheduled jobs quietly stop working.

A user-defined CSS property that participates in the cascade and inherits down the tree.

A long-running background process managed by the operating system's service supervisor.

Marking something as superseded and scheduled for removal, without removing it yet.

Named design decisions — color, spacing, radius, type — stored as data so they can be shared and re-themed.

Refractive index varies with wavelength, so a medium bends colors by different amounts.

A statement of the form "the last one" or "nothing else does this" — load-bearing, and only as good as the search behind it.

A genre whose core verb is building the machine that plays the game, turning the player into a systems engineer.

A claim is only worth something if you know what observation would refute it.

Repeatedly asking why a symptom occurred, chaining each answer into the next question until the causal chain runs out.

A fracture that stops progressing toward healing, usually because of motion, gap or lost blood supply.

Wildcard pattern matching over filenames, similar enough to regular expressions to mislead.

The measurement that arbitrates, as opposed to the artifact that merely reports.

Never attribute to malice that which is adequately explained by stupidity.

With enough users, every observable behavior of an interface becomes a dependency for somebody.

A coordinate system in which an undisturbed body moves at constant velocity, and none is privileged.

A conditional-probability puzzle in which switching wins twice as often as staying.

How much of a system's internal state can be inferred from what it emits.

Prefer the explanation with fewer assumptions, not the one that is simplest to state.

A model that fits its training data too well has memorized noise instead of learning the pattern that generalizes.

Pressure applied to a confined fluid is transmitted undiminished throughout it.

Outcomes shaped by the sequence of past choices rather than by present merit.

designing or marketing a product for a shorter useful life than it could otherwise have.

Light whose electric field oscillates in a preferred orientation, and the filters that select for it.

A previously working behavior that a change has broken.

The smallest set of steps that reliably produces a fault, and the unit of real debugging.

The energy a rolling tire loses to deformation, and why more pressure stops helping.

Explaining a problem aloud, in full detail, to a listener who cannot help — and finding the fault while explaining it.

Confining a set of style decisions to a subtree so the same component can look different in different contexts.

The claim that pre-industrial night sleep came in two blocks separated by a waking interval, and the dispute over how general that was.

A failure that produces no signal, so the absence of an error reads as success.

Looking where the light is good rather than where the answer is.

Drawing conclusions from a sample already filtered by success.

The future cost of a present shortcut, metaphorically accruing interest.

Writing a failing test first, making it pass, then improving the code with the test as a net.

Civil time is a political layer over solar time, and its rules change often enough to be data.

Reading a truncated result as if it were the whole result, so every counterexample is invisible.

A closed loop that moves heat by boiling and condensing a working fluid at two pressures.

Asking for help with your attempted solution (Y) instead of your actual problem (X), so the help solves the wrong thing.

A chain of prerequisite tasks that stands between you and the task you meant to do.