In: Engineering Psychology and Cognitive Ergonomics: 9th International Conference, EPCE 2011. Proceedings. Human Computer Interaction International Conferences (HCII-11), located at HCI International 2011, July 9-14, Orlando, FL, USA, Chapter Modeling Visual Attention for Rule-Based Usability, Pages 72-81, LNAI, Vol. 6781, ISBN 978-3-642-21741-8, Springer, Berlin, Heidelberg, 2011.