The positive and negative posters for the advertisement of the Science Museum Exhibition of Ignorance. 'There are things you know you know, there are things you know you don’t know and there are things you don’t know you don’t know.' The solutions for each of the puzzles are shown through backlights that can be turned on and off. These posters were exhibited during the end of year show for year 1 and 2 students at South Essex College.