  This paper presents a new text entry technique, namely H4-Writer, designed
for gaze controlled environments and aimed at reducing average KSPC . and
spatial footprint. It also presents an empirical evaluation of this proposed
system by using three different input devices: mouse, gamepad, and eye tracker.
The experiment was conducted using 9 participants and the obtained data were
used to compare the entry speeds, efficiency and KSPC of H4-Writer for all the
devices. Over three blocks, the average entry speed was 3.54 wpm for the mouse,
3.33 wpm for the gamepad and only 2.11 wpm for the eye tracker. While the eye
tracker fared poorly compared to the mouse and the gamepad on entry speed, it
showed significant improvement in entry speed over progressing blocks
indicating increase in entry speed with practice. A full longitudinal study was
conducted to indicate this.
  The average KSPC of all the three devices over all the text phrases entered
was 2.62, which is significantly lower compared to other hand writing
recognizing text entry techniques like EdgeWrite. An analysis of the blocks
revealed improvement in error rate, efficiency and KSPC values with progressing
block numbers as the participants got more acclimatized with the key codes for
corresponding characters.
