One-handed Interaction Techniques

“Can you enter text on a mobile keyboard with one hand, when the keys are out of reach or simply too small? With SWiM now you can!”

Mobile and wearable devices are often designed for use with two hands but we find ourselves and others using them with only one. One handed use may be due to convenience or simply due to the second hand being occupied or not available. Indeed, a recent study showed that, even when walking or commuting, 85-88% of users continued typing with one hand while the other is not available.
In the face of this we seek to explore how to support text entry with a single hand in the face of devices getting both large and small.

In this work we introduce Shape Writing in Motion (SWiM), a tilt-based gesture keyboard text entry technique that supports entering one word per gesture which is designed was use with, for example, one hand. As the name implies, it is based on the shape writing technique, commonly referred to as a gesture keyboard, which we extend to support tilt. Instead of using a finger to draw over the on-screen keyboard, we use wrist motion of the dominant hand to perform shape writing. As previously noted, the dominant hand typically exhibits finer temporal and spatial resolutions. Our tilt-based technique allows one-handed text entry and also lends itself as a suitable text entry method for remote controllers, wearable devices, and for virtual reality text entry, where users cannot see the keyboard input device.

The popularity of mobile devices with large screens is making single-handed interaction difficult. We propose and evaluate a novel design point around a tilt-based text entry technique which supports single handed usage. Our technique is based on the gesture keyboard (shape writing). However, instead of drawing gestures with a finger or stylus, users articulate a gesture by tilting the device. This can be especially useful when the user’s other hand is otherwise encumbered or unavailable. We show that novice users achieve an entry rate of 15 words per-minute (wpm) after minimal practice. A pilot longitudinal study reveals that a single participant achieved an entry rate of 32 wpm after approximate 90 minutes of practice. Our data indicate that tilt-based gesture keyboard entry enables walk-up use and provides a suitable text entry rate for occasional use and can act as a promising alternative to single-handed typing in certain situations.

Screen sizes on mobile devices have been increasing, as shown by the recent popularity of phablets (e.g., 5.7″ Galaxy Note 3 and 5.5″ iPhone 6 Plus). However, it’s difficult to hold a phablet firmly in one hand, let alone interact with it. These problems will be exacerbated if the trend of larger mobile phone screens continue. Yet, there are many occasions when the user’s other hand is encumbered or not available, such as due to a disability or when holding a bag, a cup of coffee, or an umbrella.

30 seconds teaser:

Full video:

Paper [PDF] to appear in ACM CHI 2017 conference.

Hui-Shyong Yeo, Xiao-Shen Phang, Steven J. Castellucci, Per Ola Kristensson, & Aaron Quigley, 2017, Investigating tilt-based gesture keyboard entry for single-handed text entry on large devices. in Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems. ACM Press – Association for Computing Machinery, ACM CHI 2017 Conference on Human Factors in Computing Systems, Denver, United States, 6-11 May.