> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stet.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Vocabulary

> Stable terms for Stet measurements and release decisions

These terms make a Stet result legible to both you and your coding agent.
They describe a bounded measurement, not a general statement about a model.

## Measurement inputs

* **Harness surface**: an externally controllable behavior lever, such as an
  instruction file, skill, model, reasoning setting, tool policy, or prompt.
* **Task corpus**: replayable accepted repository work, each with a pre-change
  snapshot, task prompt, and declared verification signal.
* **Slice**: the declared subset of the task corpus used for one measurement.
* **Holdout**: matched tasks kept out of iteration and used to check a finalist
  before promotion.
* **Gold patch**: the original accepted change held hidden from the agent under
  test and used as reference evidence where the workflow supports it.

## Comparison terms

* **Arm**: one configuration evaluated on the declared task slice.
* **Treatment**: the specific harness-surface configuration assigned to an arm.
* **Baseline**: a named, managed stored reference arm used for matched comparison.
  A baseline refresh records new evidence; it is not a promotion.
* **Denominator**: every declared task or arm-task cell that a stated rate uses.
  Unavailable, no-patch, and inconclusive cells remain visible rather than being
  silently dropped.

## Backends and evidence

* **Harbor**: Stet's prepared execution environment for replaying repository
  tasks with the declared setup and verifier.
* **Docker backend**: isolated container replay. It is the normal backend for
  evidence intended to inform a decision.
* **Worktree backend**: an explicitly selected local replay mode. It is not
  Docker-equivalent isolation and is inspect-only unless the Trial Result says
  the resulting evidence is decision-grade.

## Graders and dimensions

* **Grader**: an evaluator that applies a declared rubric after core verification.
* **Dimension**: a quality axis a grader evaluates, such as equivalence, clarity,
  simplicity, coherence, intentionality, robustness, instruction adherence,
  scope discipline, or diff minimality.
* **Contamination**: a signal that the trajectory may have seen information it
  should not have. It requires investigation and caps claims; it is not a reason
  to delete the affected row from the denominator.
* **Stranded results**: incomplete or repairable execution evidence that requires
  the recorded next action before it can support a decision.

## Spend and calibration

* **Spend operation**: an action that invokes a coding or grader model and can
  consume tokens. You approve these before execution.
* **No-spend operation**: status, inspection, and some evidence-preserving repair
  or re-analysis work that does not launch a new coding-agent attempt.
* **Decision-grade**: a metric has sufficient valid, complete, calibrated
  evidence for its declared decision.
* **Directional**: a metric points toward an iteration hypothesis but is not a
  promotion authorization. Directional means iterate, do not promote.
* **Noise-band**: observed differences are too uncertain or variable to support
  a directional conclusion.
* **Evidence posture**: the action strength of the whole result: actionable,
  directional, or inspect. Per-metric calibration never becomes a blended score.

See [how Stet works](/concepts/how-stet-works) for the measurement sequence and
the [release lifecycle](/concepts/release-lifecycle) for what the result can
authorize.