Last Tuesday September 11th I presented some of my research work at the Universidad San Buenaventura in Cali, Colombia. I thank my host, Sergio Bromberg, director of the GTA arts and technology group, Rocío Segovia Jiménez, director of the LIDIS Lab, and my friends Mónica Arroyave and Diego Duque for the interesting discussions around HCI and computer science teaching topics after the talk.