Marc Hassenzahl explains the fascinating concept of User Experience and Experience Design. Commentaries by Don Norman, Eric Reiss, Mark Blythe, and Whitney Hess
User Experience and Experience Design !
Zakaria, Nur Haryani, Griffiths, David, Brostoff, Sacha and Yan, Jeff (2011): Shoulder surfing defence for recall-based graphical passwords. In: Proceedings of the 2011 Symposium on Usable Privacy and Security 2011. p. 6.
Brostoff, Sacha, Inglesant, Philip and Sasse, M. Angela (2010): Evaluating the usability and security of a graphical one-time PIN system. In: Proceedings of the HCI10 Conference on People and Computers XXIV 2010. pp. 88-97.