A false-belief test used to test for the development of theory of mind in children. A child is shown a scene with two dolls (Sally and Anne), a basket and a box. Sally places a marble in her basket and leaves the room. While she is out of the room, the second doll, Anne, removes the marble from Sally’s basket and puts it in the box. The child watches all this taking place and is then asked the question ‘where will Sally look for the marble when she returns?’. A child who possesses a theory of mind will say that Sally will look in the basket because that is where she put the marble. This child realises that Sally has a false belief (i.e. the marble is not really there) but that her belief is true as far as she is concerned (i.e. she has no knowledge of its having been moved). Children with no theory of mind will say that Sally will look in the box for the marble because they will not understand that Sally’s belief about the whereabouts of the marble would be any different from their own.
The Sally-Anne test (source: www.asperger-advice.com/sally-and-anne.html)