Building bridges: HCI, visualization, and non-formal modeling : IFIP WG 13.7 Workshops on Human-Computer Interaction and Visualization: 7th HCIV@ECCE 2011, Rostock, Germany, August 23, 2011, and 8th HCIV@INTERACT 2011, Lisbon, Portugal, September 5, 2011, Revised Selected Papers (2014)