Would it be possible to give the user a quick questionaire as to what subject they are doing at the start of the year or when they register? This information could be used to streamline the questions that come up on the homepage so, for example, if you are in second year and you are only doing Fin. Maths then on your home page (and Q&A page) only Fin. Maths questions come up. If you wanted to see what other questions there are you go to the catagory of your choosing. This will make it more convinient for the user to get straight to their relevant subject's questions. Otherwise this online hotseat is a fantastic idea!