Mobile Chorded Input


  • Chords at the back/side of a mobile phone (Chorded Phone)
  • Chord input for tablets
  • Learnability of Chords
  • Keyboard Chords

Related Readings


Theoretical Backbone

Here we list references that will represent the theoretical side to inform our research. The augmented interactions framework provides us with (1) a vocabulary to articulate our interactions, (2) a starting point for our conceptual work. Implicit interaction provides us with a means to describe our interaction in terms of foreground and background, which means we can think of chords as a background interaction that augments foreground actions.


The papers listed here talk about one-handed and two-handed mobile use. We also have a more general paper that looks at how people use their hands to grasp physical objects. For one-handed usage, the focus is the physical limitations of the thumb in being unable to reach the edges comfortably, thus having an optimal area and a not-so-optimal area. Two handed use is not as constrained, as a user is able to use free movements with the hand performing the interaction.

Back of the Device Interaction and Chords on Mobile Phones

Back of Device Interaction

These papers focus on using the back of the phone to interact with the content on the screen. Dual-Surface input proposes leveraging the index finger at the back for more fine-grained selection operations. I think there's also a theme of being able to use the centre of the contact point as a precise pointer.

Text Entry

A big chunk of work on mobile chording focuses on text entry. This use case makes sense and shows an example of using chords as a trigger as opposed to being an augmentation

Bimanual Interaction

These papers use bimanual interaction in the context of mobile devices, where often one hand 'holds' and the other one 'interacts'. These I haven't read into very much.

Chord Learnability

Mobile Interaction Techniques for Mode Switching, Menu Navigations and Expert Use

Chords and Gestures on Traditional Keyboards / Piano

These papers are a bit varied - one looks at using keyboards as a chord; the next looks at using gestures like swiping to perform action; the last one looks at using a piano for keyboard entry, where chords serve to trigger commonly used words. These all show usage of (1) chording to perform common actions and (2) leveraging user expertise.

To add: GraspZoom (Rekimoto)