Training will be provided. It is the job of the Chairperson to make sure that the people in the room know what is going on, keep track of where they are in the process, and ensure that all substantive points are heard while avoiding spending time on redundancy and minor grammatical points. Rapporteurs are the secretaries of the plenary session. After the Working Party or Plenary is over, the Rapporteurs need to compare notes and make sure that they have an accurate record of the debate and votes. Runners are not always used, but are most useful.
Runners also count votes when necessary.