How can I implement a scarcity pattern in the gamification of a forum

Question

StackExchange uses a scarcity design pattern when new users are restricted in how many comments, up votes, and down votes they can post contingent on their score/rank. My client wants to implement similar gamification of scarcity pattern in which users get a weekly allowance of credits, and there's a fixed cost to post replies in a debate forum. This is intended to promote higher quality content, based on the idea that scarcity motivates more carefully considered responses.

I have expressed doubts to my client that this game mechanic will be successful at motivating the target behavior, which is higher quality content. I have suggested using a positive feedback mechanism to reward the target behavior, rather than using scarcity to discourage dis-preferred behavior.

I would like to understand the trade-offs in Gamification between motivating desired behavior through positive feedback (e.g. badges) versus discouraging dis-preffered behavior through negative feedback (e.g. scarcity pattern). I am interested in specific examples of success or failure of either mechanism as it relates to this question. (No I am not trying to start a discussion, thank you for your concern though.)

As an example of a precise testing of the above question, one could use the SE API to look at user behavior patterns before and after specific positive and negative feedback events. Since SE uses both types of game mechanics, we could look at how user behaviors may change after such events (assuming they're included in the SE API).

Answer 1

First of all, your client's idea will not work. There is no realistic way to predict how many posts a user is going to want to make, so if you set the credit system to allow people to only post ten posts per week, there is always going to be someone who will only want to post five posts. As a result, since the limit doesn't affect them, they will post five low quality posts. What it will do is it will limit the amount of low quality (and high quality) posts you will get, because people can only post so many posts, but it will not eliminate the low quality posts completely.

Now, the answer to your question about whether it is better to encoradge people do do things you want, or to discourage people if they do something you don't want is... the best solution is to do both.

If your site only rewarded people if they posted high quality content, then people could post really low quality content and get away with it. In addition, the people who are posting low quality content will have their own idea on what constitutes as good content, which will probably be different than your own. The quality of bad content that those people will post will change the average quality of content in your site, and with it, your site's perception of what good content it. Your site will have a serious problem.

However, if you only punish bad content, people will have no excuse to post anything that isn't better than average, and your site will not be a good site either.

This question is asking which one is more effective, however, and I have to say that positive feedback is more effective. The reason why is because not getting positive feedback is a form of negative feedback, and while it's not as effective as say, a down-vote, having no feedback at all while other people are getting a lot of positive feedback can motivate people to try harder. With only negative feedback, people are only motivated to avoid getting negative feedback, which can lead to a lot of average content.