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| GI'97 Online Papers |
The Immediate Usability of Graffiti
Abstract
We present four empirical measures of the immediate usability of
Graffiti, a character recognizer for pen-based computers. Since speed
is fully controlled by the user, we measured the accuracy attainable
after minimal exposure. The first measure, 79%, is the inherent
accuracy, or the extent to which Graffiti strokes match letters in the
Roman alphabet. The other three measures were obtained in a formal
experiment. We asked 25 subjects to enter the alphabet five times into
a pen-based computer under three conditions: (a) following one minute
studying the Graffiti reference chart, (b) following five minutes of
practicing with Graffiti, and (c) following a one week lapse with no
intervening practice. The accuracy was 86%, 97%, and 97%,
respectively. These are very respectable figures given the limited
exposure of subjects. The third figure represents complete retention
following a one-week lapse. We present analyses of the errors on a
character-by-character basis, noting that poor performing characters
should be emphasized in tutorials and other learning aids for new
users.
The Paper
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HTML version
@inproceedings{MacKenzieZhang-gi97,
title = "The immediate usability of graffiti",
author = "I. Scott MacKenzie and Shawn Zhang",
booktitle = "Graphics Interface",
editor = "Wayne Davis and Marilyn Mantei and Victor Klassen",
year = "1997",
month = "May",
pages = "129--137"
}
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