In 1999, the Hole in the Wall (HIW) experiments in children's learning, was first conducted. In the initial experiment, a computer was placed in a kiosk in a wall in a slum at Kalkaji, Delhi and children were allowed to use it freely. The experiment aimed at proving that children could be taught by computers very easily without any formal training. Mitra termed this Minimally Invasive Education (MIE). The experiment has since been repeated. HIW placed some 23 kiosks in rural India. In 2004 the experiment was carried out in Cambodia.