Over the past two decades, interactions on and around large high-resolution displays have gained
increasing levels of attention in research and in practice. This thesis explores and compares
interaction techniques for large displays that operate up-close and at a distance. More specifically,
the focus of this thesis is on three aspects of large display interactions: (1) Improved Mid-Air Text
Entry; (2) Improved Understanding of Input Modalities; and (3) Extended Boundaries of
Interaction.
To improve support for mid-air text entry, Paper 1 conducted a design space analysis, and
three mid-air text entry methods were evaluated to establish a baseline for mid-air text entry
performance. The most promising technique, Projected QWERTY, reached a text entry rate of 13.2
Words Per Minute (WPM). Paper 2 aimed to improve mid-air text entry rates by adapting Word-
Gesture Keyboards (WGKs), a previously successfully text entry method for touch- and pen-based
input, to work as a technique for mid-air text entry. With a text entry rate of 20.6 WPM after 10
sessions of text entry, the mid-air WGK provided faster text entry rates than previously evaluated
methods for mid-air text entry. An improved version of the keyboard even showed text entry rates
of 28.1 WPM on the first session of an accelerated learning study where a limited set of phrases
were repeatedly transcribed. Paper 3 build on the result from Paper 1 and Paper 2, and propose new
directions for text entry research for large displays.
To improve understanding of the differences between input modalities for large displays, the
mid-air WGK was compared to a touch-based functionally equivalent WGK. The touch-based
keyboard was found to be significantly faster than the mid-air WGK, indicating that touch based
interaction may be preferable for text entry. However, future work could potentially increase text
entry rates of the mid-air keyboard by studying and identifying the specific properties that resulted
in the performance benefits of the touch-based keyboard. Paper 3 also proposed the Back Of the
Hand (BOH) as a novel interaction modality for large displays that could have some of the
advantages of both touch and mid-air interaction. To assess the potential of this novel interaction
modality, Paper 4 presents a tracking solution that was developed and tested as an input method for
smart watches. Further studies are needed to explore the potential interaction techniques supported
by this novel tracking solution, and assess its potential to work as a new input modality for large
displays.
Finally, Paper 5 presents Off-Limits, a novel interaction concept for large displays that uses
off-screen pointing to allow direct reach of content that reside outside the display boundaries, taking
advantage of users’ perceived location of off-screen content. Off-Limits was found to provide
significant benefits over touch-based interaction. The results show that an extension of interactions
beyond the boundaries of the display can increase users’ performance.