An Augmented Knights Castle (AKC) play set was adapted so that children with 
autism can configure programmable elements. This is compared with a 
non-configurable AKC. When the system is configurable, less solitary play and 
more cooperative play occurred. Configurability is a key factor in design for 
children with autism allowing greater individual control and more socially 
oriented behaviour. We suggest that tangibles provide a safety net for 
encouraging social interaction as they allow for a broad range of interaction 
styles.