Head tilting for interaction in mobile contexts

Abstract

Developing interfaces for mobile situations requires that devices are useable on the move. Here, we explore head tilting as an input technique to allow a user to interact with a mobile device 'hands free'. A Fitts' Law style evaluation is described where a user acquires targets, moving the cursor by head tilt. We explored position and velocity control cursor mechanisms in both static and mobile situations to see which provided the best level of performance. Results show that participants could successfully acquire targets using head tilting. Position control was shown to be significantly faster and more accurate in a static context, but exhibited significantly poorer accuracy and longer target acquisition times when the user was on the move. We further demonstrate how analysis of user's gait shows consistent targeting biases at different stages in the gait cycle.

The effects of walking, feedback and control method on pressure-based interaction

“…Within past PBLT research, nearly all studies have used the same control/interaction method, known as Positional control. However, results from pressure-based shape translation [13] and targeting through head tilt [4] have suggested that a velocity or Rate-based control may allow for better control of pressure or linear targeting (respectively), especially when the user is mobile. Therefore, in this paper we present two parts of one study looking at pressure input on mobile devices: one looking at how walking affects our ability to control pressure-based input and which control method allows for better control; and a second testing whether the same mobile interaction can be carried out with only audio feedback.…”

Gesture-Based Interfaces: Practical Applications of Gestures in Real World Mobile Settings

“…Similarly to the wrist rotation study, users interacted both while static and mobile. Detailed statistical results can be found here [4]. There were significant differences found in the accuracy data between the static and mobile conditions using both position and velocity control.…”

The effects of walking and control method on pressure-based interaction

“…Crossan et al [2] found that head tilt using rate-based control produced better accuracy than positional, at the cost of slower selection time, when users were walking. Conversely, they found that positional control allowed for superior accuracy and selection time when users were sitting.…”

“…This study found that walking negatively affected accuracy when selecting 2 levels of pressure. Other work looking at how walking influences mobile interaction has also found negative effects on control accuracy when tapping on-screen with a finger [3] and during linear targeting via head tilt [2]. We therefore wanted to investigate 1) how mobility influences our ability to control pressure; 2) which control method, positional or rate-based, allows for more stable and accurate control of pressure when mobile; and 3) whether this knowledge can be used to design non-visual mobile pressure interaction as it has been shown that users can accurately apply pressure using only audio feedback while sitting [7].…”

“…They were allowed to rest their arms on either their legs/knees or a desk in front of them to provide stability, but could not rest their wrists or the device while interacting. The mobile condition used a similar design to Crossan et al [2] as it requires divided attention between task and navigation. Participants were asked to walk in a marked 4m x 3m figure-of-eight route indoors while they interacted with the device.…”