Forum

The Q and A forum doesn't allow students to see responses to a topic (the Question) until they have posted a response. Forums have a period of time after posting in a forum that the user can edit their posts. The default is 30 minutes but can be as low as 1 minute. After the editing time has passed, the subscriptions for the post are emailed out. Allowing editing of your own post for a set time is a good thing. The problem in the Q&A module is that students can post something, including garbage like 'asdf', then see other student's responses, and then edit their own post to submit an answer. Students can also delete their posts. This allows cheating. There are no great workarounds right now. There isn't a permission that can be set to prevent students editing their own posts. There is a permission that controls deleting posts but would need to be set anew for each Q&A forum. There is a patch posted in this tracker issue:
http://tracker.moodle.org/browse/MDL-9376
Anyone that thinks this is an important issue should vote on it and give comments on potential solutions. It would be nice if a core developer could comment on the patch and give feedback on the solution. Especially on improvements that would allow it to be included in core and what would be the preferred solution type.

Workarounds:
1. Set max editing time of posts site wide to one minute.
For sites with the default of 30 minutes, this would be a big change and effect everyone. The editing time is generally seen as good. Fast cheaters would still be able modify there posts, especially if they had the post partially answered and were just cribbing a few parts. Students could delete their post and would have longer to crib answers. Although that could be denied using permissions.

2. Faculty tell students not to edit their Q&A posts and for faculty set permissions so that students can't delete their own posts.
Faculty can go under reports and see who has edited or deleted their own posts, but what was edited and the intent cannot be proven. Faculty would need to know about the issue. Not really a fix but the best we can do right now.

Potential fixes
1. Don't allow students to edit or delete Q&A posts.
Solves the problem but students might be surprised by this since it is different than other forums. Students may legitimately be using the editing time to find last second errors.

2. Don't allow students to see other's posts until they are no longer able to edit or delete their post.
The plus side is that the logic for whether the student can edit their own post is already there. The downside is that it would slow down the Q&A forum process, especially in the cases where students were to reply to other student's answers.

3. Use Solution 2, but add a student option that ends the editing/deleting period for the post. This could be when the post is created similar to where the 'Mail now' option for teachers is and/or after posting next to the edit and delete options for a post.

This is also discussed here:
http://moodle.org/mod/forum/discuss.php?d=131563