HP Gesture Keyboard - Manual (Page 2)

Gesture Keyboard - User centered design of a unique input device for Indic
Scripts
Ashish Krishna 1 , Rahul Ajmera 1
Human Factors International
4
th
Floor, Chemtex House
Hiranandani Gardens
Mumbai – 400 076
{ashish.krishna, rahul.ajmera}@hp.com
1 Currently at HP labs
Sandesh Halarnkar and Prashant Pandit
HP labs
24, Salarpuria Arena,
Hosur Main Road, Adugodi,
Bangalore, India
{sandesh.halarnkar,
prashant.pandit}@hp.com
Abstract
Indic text input presents a unique challenge in the field of keyboard design because of the number of standalone
characters, conjuncts, matras, and symbols. It poses a huge challenge to the HCI practitioners to accommodate the
humongous array of Devnagari characters in a keyboard. Solutions for input in Devnagari scripts using a physical
keyboard have been around for a while but none of them have emerged as a standard mechanism due to several
usability related concerns. In this paper we have described the design of a new gesture based keyboard, which has a
dual input mode 1. Gesturing 2. Tapping. The “gesture keyboard” concept is based on partial hand writing
recognition as well as touch-typing paradigms. Conceptually, it is a stylus sensitive keypad that supports tapping for
getting the base consonants and some symbols, while it also recognizes handwritten matras as per handwriting
recognition methods. This paper also reports the findings of the user study, which was carried out to find the
optimum sizes of the keys and layouts.
1 Keywords
Devnagari text entry, Gesture Keyboard (GKB), Matras, Modifier, Syllable, IMEs
2 Introduction
Given the well-understood challenges of achieving high accuracy with recognition of natural handwriting and
dealing with the great variability in writing styles, a number of alternative schemes (generically called Input Method
Environments or IMEs) have been developed for English and some Oriental scripts. Some of these are based on
development of simplified gestures (e.g. Uniscript and Graffiti for English), others are based on interactively
arriving at the intended character using partial handwriting input or other cues from the user.
This new keyboard introduces a paradigm shift in text inputting methods. We have developed a prototype for
Devnagari, which takes best of both worlds; it takes cues from handwriting recognition (matras formation) and
touch-typing (base characters). The new design has all the base consonant keys and the user is required to make a
Matra (a gesture) on top of it, to make a syllable. Thus significantly reducing the need to hunt and peck and leading
to quick learnability, retention and reduced hunting load.
The Gesture Keyboard is not presented as an alternative to the conventional English keyboard but has been proposed
as a peripheral input device. The user would have an additional device (GKB) connected to his workstation along
with the regular ASCII English keyboard and a mouse as shown in Figure below.