A
B
C
As shown in Figure 4, in the
first study, when presented with
the control interface, 63 percent
of the time participants selected
the checkbox when choosing their
candidate. Thirty-one percent of
the time participants selected
the button, and only 6 percent of
the time participants selected the
candidate’s name. However, when
the checkbox was removed in the
experiment interface, 61 percent of
the time participants selected the
candidate’s name, followed by participants selecting the button itself
39 percent of the time.
In the second round of studies,
86 percent of the time participants
selected the checkbox when it was
provided as an option. When the
checkbox was removed, 84 percent
of the time participants chose the
candidate’s name.
In total, 55 people participated
in the studies. Out of the 156
recorded touches in the control
studies, 72 percent touched the
checkbox, 6 percent touched the
candidate’s name, and 22 percent
touched the button. Out of the 153
recorded touches in the experiment studies, 31 percent touched
the button, and 69 percent touched
the candidate’s name.
Interestingly, regardless of the
presence or absence of a checkbox, a percentage of the time ( 5
to 6 percent) study participants
elected to touch the candidate’s
name as opposed to the supplied
checkbox. In a real election, if
5 percent of the voters touched
the candidate’s name and some
of these selections resulted in
unintentional voter selection,
this could be more than enough
votes to change the outcome of a
close election, given the significant number of people who do not
verify their ballot choices [ 2, 3].
The findings suggest that ballot
design may influence how voters
interact with controls on an elec-
tronic ballot. In both studies, more
voters selected the checkbox when
it was present, followed by select-
ing the button itself, with an even
smaller number touching the can-
didate’s name. However, when the
checkbox was removed, more vot-
ers selected the candidate’s name
than the button.
• Figure 5. Design recommendations for
electronic ballot buttons. a) Design option
1 before selection b) Design option 1 after
selection c) Design option 2 before selection.
November + December 2012
interactions
Improving Design, Minimizing Error
The results of this study suggest
that the use or absence of checkboxes may influence user interactions with an electronic ballot.
However, some users still elect
to select a candidate’s name. We
therefore suggest that candidates’
names be centrally located on buttons, both vertically and horizontally to minimize unintentional
voter selections. If checkboxes or
other images are used, they should
be vertically centered as well.
Due to limited screen real
estate, ballot designers may minimize gap space between buttons
to accommodate all candidates in
a contest. This design choice provides the opportunity for finger
roll, as a voter’s finger may roll up,
down, or sideways depending on
the positioning of the touchscreen.
The recommendations presented
here are based on the use of sufficiently large buttons within the
design. Sufficiently large buttons
are buttons that are large enough
to provide space for a voter’s finger
to roll on a selection without rolling into the area of the adjacent or
surrounding buttons. Illustrations
of recommended designs are presented in Figure 5.
In design option 1, the text is
horizontally and vertically centered within each button (Figure
5a). Centering text in this way
reduces unintentional voter error