<XML><RECORDS><RECORD><REFERENCE_TYPE>3</REFERENCE_TYPE><REFNUM>7655</REFNUM><AUTHORS><AUTHOR>Crossan,A.</AUTHOR><AUTHOR>Murray-Smith,R.</AUTHOR></AUTHORS><YEAR>2004</YEAR><TITLE>Variability in Wrist-Tilt Accelerometer-based Gesture Interfaces</TITLE><PLACE_PUBLISHED>Mobile HCI, Glasgow </PLACE_PUBLISHED><PUBLISHER>Springer Verlag</PUBLISHER><LABEL>Crossan:2004:7655</LABEL><ABSTRACT>In this paper we describe a study that examines human performance in a tilt control targeting task on a PDA. A three-degree of freedom accelerometer attached to the base of the PDA allows users to navigate to the targets by tilting their wrist in different directions. Post hoc analysis of performance data has been used to classify the ease of targeting and variability of movement in the different directions. The results show that there is an increase in variability of motions upwards from the centre, compared to downwards motions. Also the variability in the x axis component of the motion was greater than that in the y axis. This information can be used to guide designers as to the ease of various relative motions, and can be used to reshape the dynamics of the interaction to make each direction equally easy to achieve. </ABSTRACT></RECORD></RECORDS></XML>