There are five possible roles a user can have in a discussion:
Owner
The Owner is the creator of a discussion, with the same rights as an Admin. An Owner can choose another user to take over the ownership of a discussion (see Transferring Ownership of a Discussion). There can only be one Owner in a discussion at any time.
Admin
Admins have all the rights of Editors, as well as various rights relating to the management of the discussion. Admins can modify the discussion settings, change the rights of users and invite new members. Admins can also change the discussion between single- and multi-thesis forms, write tags and change the cover image. They are also able to accept suggested claims/comments, or send them back for review.
Editor
Editors have full rights to create, edit, move and delete claims, as well as to comment or mark claims for review.
Writer
Writers have the right to create claims and move, edit or delete their own claims. They can also comment on any claims in the discussion, and in the discussion chat. Writers are also able to link claims in other locations in the discussion.
Viewer
Viewers have limited rights in a discussion but are able to vote on all claims. This is the default setting for all logged in users, and applies to public discussions even if a user does not have an invite to the discussion. If a Viewer wants to add a claim, they will need to ‘suggest’ it. See Suggesting Claims for more information. A Viewer can also suggest an improvement to a claim - a comment only initially visible to the Admins of a discussion (see: Suggesting Improvements).
A user will have the highest participant rights their account has been afforded. For example, if a user is an Editor of a discussion, but also a member of a Team with Admin rights, they will not be restricted to the rights of an Editor.
You can always adjust the user rights of Teams and individuals in the Discussion Settings - open the Discussion Menu and select ‘Discussion Settings’. Select the ‘Invites & Permissions’ tab, and then make the changes to permissions by using the drop-down menus by each user’s name.