Rest assured it will NOT be like appearing on Radio 4's "Just a Minute" where you are given a subject and expected to talk on it without repetition, hesitation or deviation. It will be 'unseen' inasmuch as you will receive the subject matter and preparation materials at some time before you are expected to make the presentation and I am pretty sure you will have adequate time to prepare. No one can tell you exactly what the presentation will be about but it could, for example, involve being given a copy of RAISEonline or an OfSTED Report or some other data and asked to identify key points. Now please do not assume that is what you WILL be given, we just don't know. See your preparation for the presentation as time-limited rather than "under pressure". You will be given exactly the same amount of time and limitations as all other candidates. Try to keep a clear head and bear in mind that undertaking this interview is your choice, not anyone else's. In other words, try to keep ownership of all this in your own mind. You can always start your presentation with the words "In the time allowed me to prepare this presentation I consider that...." Depending on the nature of the task, you could always finish with something along the lines of "I believe that a, b and c would be issues worthy of further investigation and more detailed analysis," hence showing what you WOULD prepare or investigate if additional time were given. Good luck.