Hi Kristine,
Inviteee roles can be assigned only when scheduling from Web and not through Outlook. When scheduling from Outlook, the roles will be assigned automatically based on the meeting type you have selected:
Collaborative:
Owner: Moderator/ Speaker
All Invitees: Presenter/ Speaker
Presentation:
Owner: Moderator/ Speaker
All Invitees: Audience/ Speaker
Webinar:
Owner: Moderator/ Speaker
For first 2 Invitees: Presenter/ Speaker ( not valid for non-profiled invitees)
All other invitees: Audience/ Listener
HTH,
Natasa