Actor types

All terms live in the bdm: namespace; the canonical id of initialized is bdm:initialized.

Actor type	Description
Agent	A specific agent — usually the human participant; may be an AI/automated participant.
Group	A collection of agents acting together (xAPI compatibility; rare).
Engine	The runtime software acting on its own (web viewer, Godot viewer, game engine, CLI runner).
Orchestrator	The backend service that schedules Activities, mints RuntimeInstances, manages submission.
Researcher	A researcher acting on the data (post-hoc annotation/correction).