Figure 1: typical computer setup with a gesture keyboard

2.1Need for a Devnagari input device

Computer usage in India is almost entirely in English and is restricted to the English-speaking, upper and upper- middle class people. This stands in direct contrast with the demand for communication in Indian languages. Census data for the year 1991shows that English is the first language for only 0.02% of Indians and second and third language for 8% and 3% respectively. Hindi TV programs claim all the top 10 slots in television program ratings. Circulation of daily English newspapers had a market share of 15% in the year 2002. (Chand, Ganu, Joshi, Mathur

&Parmar, 2004) 2001 census indicates that almost 70% of the Indian population specks 5 major languages i.e. Hindi, Bengali, Telugu, Marathi and Tamil with Hindi being the most spoken language at 40.22%. (http://www.censusindia.net/language.html)

2.2Difference with roman script

Using a standard keyboard for Devnagari scripts creates usability issues, as the Devnagari Script possesses some conceptual differences from the Roman script.

Some of these are summarized below:

•The concept of matras (character modifiers) has no parallels in the Roman script.

•Each character has a shiro rekha (the top bounding line on Devnagari characters) on top of it.

•Character modifiers, basically matras and other special characters, can occur before, on top, below or after the main character that they modify. (Deb and Deshwal, 2003)

•Since in the written form there is no clear specification of the sequence in which modifiers should be added to the consonant, sequential entry modes like a keyboard would not fit the users mental models

•More than one modifier can be attached to one consonant

2.3Issues with using an Inscript Keyboard

Current Indian language typing solutions have a steep learning curve. According to Arjun Mahanto, the Hindi Officer in IIT Bombay, learning to type requires approximately fifty hours of training and practice for a person to reach speeds of 25 words per minute. This is too much of a barrier for ordinary people and only professional typists are willing to make this investment. (Chand et al., 2004)