# OBSERVATION

A keyed READ scheduled at execution checkpoints, or an address-label declaration.

Canonical HTML: <https://determica.com/docs/types/observation>

- Family: Logical
- Physical type: JSON

A keyed READ scheduled at execution checkpoints, or an address-label declaration.

## Used by functions

### Returned as output

- [observation_fact](/docs/functions/observation_fact.md) — Declares a human-readable label for an address without scheduling a READ.
- [observe](/docs/functions/observe.md) — Schedules one keyed READ at both the pre and terminal execution checkpoints.
- [observe_after_step](/docs/functions/observe_after_step.md) — Schedules one keyed READ at the checkpoint after a zero-based PROGRAM step.