**Main ideas** - The main challenge of Natural User Interfaces is that possible actions are not clear. ^d0d75a - [[Don Norman]] argues that the advantage of the GUI is not the implementation of graphics per se, but the fact that all possible actions are clear and evident to the user. - Another short coming is that if a gesture gets no response, or the wrong one, there is not feedback **Reference** @ARTICLE{Norman2010-sh, title = "Natural user interfaces are not natural", author = "Norman, Donald A", abstract = "``I believe we will look back on 2010 as the year we expanded beyond the mouse and keyboard and started incorporating more natural forms of interaction such as touch, speech,...", journal = "Interactions", publisher = "Association for Computing Machinery (ACM)", volume = 17, number = 3, pages = "6--10", month = may, year = 2010, language = "en" }