Cannot delete one's own comments made on study elements directly from that study element (i.e., comment made on a study's IV, DV, N, Power, or Effect Size). However, you can delete comments made about a study's components (i.e., data, materials, registration, disclosure).
Steps:
- Leave a comment an existing or newly created article.
- Try and delete the comment
Notice there's no way to delete the comment you just left (though you can delete it from the user profile page, which will likely not be obvious to users). And, again comments left on a study's components can be directly deleted from that study's component.
Note: If a comment has replies, then a comment cannot be deleted, even by the original author of the comment; only admins and editor users will have the ability to delete comments with replies (this will be implemented in the future as we still don't have an editor user class I believe)