Clubs and perspectives
Clubs in Duolingo is a great tool as it increases competition and motivation. The new option to comment using text boosts the challenge to create a small community of friends or not. You can organize real contests in a Club. You can put a goal to achieve by the members. For instance, who can gain 1000 XP this week? Another option that is a privilege of the admin is to remove members. Yes, you can remove members that are annoying, trolls, or harassing members. But you cannot as admin remove them forever. These members can come back with the same or other name and do the same. The admin can delete comments, and this is very useful in these cases.
What about using removal penalty as a tool for motivation? I mean, every member that has been removed to come back with 0 XPs so as removal can act as a motivation to practice more. Unfortunately this is not made so. The removal is not a penalty that the admin has the privilege to "punish" a member that does not obey the rules or it makes trouble to the club. Of course this privilege makes the admin too powerful, and maybe he can use it for his own good, if he wants to remove rivals. In these cases the best you have to do is to change club. It would be good to have a previous knowledge about the club before entering. That's why it is necessary the field in the description to be more extended. It is just a couple of characters at the moment. I propose Duolingo to make a whole text field, where the admin can publish a description, a contest, the results of the contest etc. By time Clubs can discuss language issues, or even organize events. It is a great idea anyway!