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352 CHAPTER 12 Automated data collection methods

FITTS' LAW, CHILDREN, AND MOUSE CONTROL—CONT'D
Their study involved 13 4-year-old children, 13 5-year-old children,
and 13 adults (between 19 and 22 years old). Participants were asked to
move the mouse from a home area to a target to the right. Targets had three
diameters—16, 32, or 64 pixels—with three distances between start and
target—128, 256, or 512 pixels. Participants completed 45 tasks in roughly
15 minutes—about the limit of the attention span of 4- to 5-year-old children.
Data collected measured accuracy (did they press the button inside the target),
time, and measures of reentry (leaving and reentering the target). Software
developed for conducting the experiments also collected mouse motion data
sufficient for reconstructing mouse movement paths.

FIGURE 12.10
Typical paths illustrate greater reentry rates for children: (1) adult, (2) 5-year-old, and
(3) 4-year-old (Hourcade et al., 2004).
From Hourcade, J.P., Bederson, B.B., Druin, A., Guimbretière, F., 2004. Differences in pointing task
performance between preschool children and adults using mice. ACM Transactions on Computer-Human
Interaction 11 (4), 357–386.