I think your navigation, layout and terminology is confusing users. I think you need to make the following improvements:
- make the front page and main navigation focused around the three main reasons visitors are there (Start a quiz, add questions, see leaderboards), I suspect the general user doesnt care about your twitter link, searching for questions, about, help (move those all to a sub navigation somewhere else). The front page could be split in two, one side to answer and the other side to add questions
- remove the add questions interface from the answer screens as again it is confusing (see aside below)
- I think the term "mashed" is a bit confusing when you mean "created"
Aside: I just tried your link above and then picked the first
topic which took me to:
As a non logged in user I have the following issues:
- you are randomsing the answer display but the answers people
have written include "none of the above" which wont always appear as
the last answer
- I have a "well done" section on the right when I haven't
answered a question?
- if I scroll down I get a message "You have answered every
question we have on Science.", I haven't answered any?
- if I continue to scroll down I can now add a question, but I am
in the middle of answering a quiz, that doesn't make sense to me