{
  "context": "This criteria evaluates how well the engineer uses aiortc's RTCRtpTransceiver API with direction control to manage role-based media transmission in a video conference system. The focus is on using addTransceiver() with appropriate direction parameters and dynamically updating transceiver directions to implement the three participant roles.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Uses addTransceiver",
      "description": "Uses RTCPeerConnection.addTransceiver() method to create audio and video transceivers rather than relying on addTrack() or implicit transceiver creation",
      "max_score": 20
    },
    {
      "name": "Sets transceiver direction",
      "description": "Sets the direction parameter when creating transceivers using addTransceiver(kind, direction=...) or sets the transceiver.direction property to control media flow (sendonly, recvonly, sendrecv, or inactive)",
      "max_score": 25
    },
    {
      "name": "Presenter role configuration",
      "description": "Correctly configures PRESENTER role with send-only transceivers for both audio and video using direction='sendonly' or equivalent",
      "max_score": 15
    },
    {
      "name": "Viewer role configuration",
      "description": "Correctly configures VIEWER role with receive-only transceivers for both audio and video using direction='recvonly' or equivalent",
      "max_score": 15
    },
    {
      "name": "Moderator role configuration",
      "description": "Correctly configures MODERATOR role with bidirectional transceivers for both audio and video using direction='sendrecv' or equivalent",
      "max_score": 10
    },
    {
      "name": "Dynamic direction updates",
      "description": "Changes transceiver direction dynamically by updating the transceiver.direction property when implementing role transitions in the change_role() method",
      "max_score": 15
    }
  ]
}