Brief on Accessible, Verifiable Voting
Gregg Vanderheiden Ph.D.
January 15, 2007
(rev Feb 11, 2007)
Much has been written about both accessible voting and verifiable voting technologies
and procedures. Some of these documents seem to say or imply that we much choose
between accessible voting and verifiable voting. This submission is made to
refute this assertion or implication and to provide one model for voting that
maximizes both accessibility and verification.
Specifically his document demonstrates that accessibility and verifiability
need not conflict with each other. Although particular access or verification
techniques might not be compatible, both access and verification can be achieved
together if the proper techniques are used.
Importance of trust
It is important that any solution proposed must not only be trustworthy and
secure but it must look trustworthy and incorruptible, even by those who are
non-technical and who distrust technology Since "everyone"; includes
people with all levels of technical prowess, and because the fear of vote-fixing
is of most concern with regard to software, it is unlikely that any means of
verifying the vote or securing the vote through software will allay all people's
concerns. Any cost savings in a paperless system will be lost in additional
costs resulting from lack of confidence in the voting system.
The approach recommended provides a mechanism that combines the accessibility
of electronic voting with the verifiability of paper ballots. In addition it
reduces errors in tabulation by using the machine to fill out the ballot so
that the result is much clearer and unambiguous.
The approach is based on the following propositions.
- The voter will have most confidence that their vote has been recorded properly
when they can read the result on paper which is then counted.
- The voter(s) will have most confidence in a recount if the individual votes
can be recounted by humans in order to check the machine count.
- Voters are less concerned about people in every precinct being corrupt in
the same way (e.g. all losing or changing paper votes the same way) than they
are with the possibility of central software based corruption where there is
no paper trail.
- OCR can be essentially perfect (99.9999+% accurate) when the task is not
to recognize unknown text but just to find the best fit of what
is on the printed ballot and what the candidates name for each office are (as
they would be printed on the ballot).
The following are the steps in the actual ballot casting process.
- The voter enters the voting place, is confirmed as eligible to vote, and
is directed to a voting station. (if they are unfamiliar, a training
station can be used).
- The voter uses a voting device with electronic display to present the race
and referenda choices and fill out the ballot.
- The electronic voting device prints out a small card (ballot) that lists
only the names of the people and referenda that the person voted for. This
printout would be in the persons native tongue but may have two languages
(one on front and one on the back) if necessary to avoid language patterning.
- The voter takes the card from the machine and is able to read the names
of the races (and referenda) and the choice they made for each.
- The voter carries the ballot over to the "ballot submission"
area where they insert the ballot into the ballot scanning and counting machine.
- The actual printed text (that was read by the voter) is read using Optical
Character Recognition (OCR) and matched against the possible choices for each
race or referenda.
- The ballot card is then captured in a secure container for later spot checking
of machines or for use in recounts.
Potential accessibility accommodations for each step
- Users who need to, can practice prior to voting
- The voting device can have flexible interface options that accomodate a
wide range of user abilities:
- "Voice confirm" feature that announces (in the headphones) the user's
choice each time they make a selection on screen.
- "Touch and hear" feature that reads any text aloud when it is touched
- Voice output through headphones as voter moves from race to race and
choice to choice.
- A simple 8 button interface
- (2) Fwd and Backward through races
- (2) Up and Down through choices in a race
- Mark or unmark a choice
- Jump to end for summary and closeout
- Go back to Start
- NOTE 1: This interface could be on a cord to allow positioning in
the lap or other location to facilitate operation.
- NOTE 2: This 8 button interface approach is compatible with most
all voting machine formats including tablets, full page ballots, touch
screen and other formats.
- Ability to use alternate input devices through isolated input port.
Users can connect personal switches/controls but the switches are constrained
to acting as substitutes for the controls on the voting machine.
- Secure input can be done through simple single switch jacks and
through other special ports that are isolated from all system buses
and only allow parallel activation of the user voting controls.
- This can allow a greater number of individuals to vote independently.
A standard mapping of switches can be created to facilitate this or
a hybrid 'standard or user specific" mapping technique such as
will be used on the new Library of Congress Digital Talking Books
could be used.
- For those unable to physically handle a ballot, a poll worker can use a
sleeve to remove the ballot and carry it to the ballot submission station
for the person and insert it.
- For those who cannot read the ballot, a reading station that is an extension
of (but at a short distance from) the ballot scanning and counting machine
can be available. At this reading station:
- A simple lighted magnifier can provide access for those with low vision.
- An accessory on the counting machine (connected by a cord) can provide
the ability to have the ballot read to the user on headphones using the
same OCR that will read and count their final ballot. Simple controls
can allow them to step through the races and listen to their choices.
Using the counting machine electronics for reading the ballot reduces
cost and lets the person know exactly what the counting machine will read
- The vote card has a corner clipped which makes it easy for the person to
hold it face down. The scanner however will accept the card in any orientation.
It also has a funnel like input to allow easy insertion with minimal physical
This implementation is not the only possible implementation but is illustrative
of how the key features can be implemented. The key factors for any solution
- The ballot choices are presented to the user by a voting machine with flexible
display capabilities and flexible input options that can meet the needs of
people with the largest possible range of abilities.
- This voting machine gathers the users choices and prints a clear unambiguous
- The ballot is printed on paper (or other similar medium) where the user
can read exactly who they voted for in a permanent form.
- The printed text that they user reads and confirms is what is counted.
Not some other representation.
- The printed ballot that the user confirms and that is counted is kept for
spot checking and recounts- both of which CAN be done by human to check machines
on either a sampling or on a comprehensive basis as needed.
- There is a ballot reading station that allow users whose disabilities would
prevent them from reading the printed ballot directly, to read the ballot
using a device that allows alternate presentations.
Following this model it is possible to create a voting system that is completely
verifiable yet accessible. No system currently provides these features. Several
could be readily updated to do so and most could evolve into a format that would
support the key features of this approach.
About the author
Gregg Vanderheiden Ph.D. is a Professor in the Industrial and Systems Engineering
Department (Human Factors Program) and the Biomedical Engineering Department
and is the Director of the Trace Research & Development Center at the University
of Wisconsin-Madison. He is the PI for the Rehabilitation Engineering Research
Center on Information Technology Access, and co-PI for the RERC on Telecommunication
Access. He served on the IEEE and HFES Voting Standard Accessibility working
group, and has provided input to the Federal Elections Commission voting standards.
Dr. Vanderheiden has been engaged in R& D on accessible voting since 1998,
and demonstrated the first cross-disability accessible voting system in a plenary
presentation at FOSE in April 2000. He also served on the FCC's Technological
Advisory Council, was a member of the Telecommunications Access Advisory Committee,
the Electronic Information Technology Access Advisory Committee, and the Telecommunications
and Electronic and Information Technology Advisory Committee of the US Access
Board, and served on the steering committee for the National Research Council's
Planning Group on "Every Citizen Interfaces," co-authoring the NRC's
More Than Screen Deep report. Recent achievements include co-authoring of the
W3C's Web Content Accessibility Guidelines, Development of the Accessibility
Features in Windows and Macintosh control panels, development of the EZ (R)
Access techniques for providing cross-disability access in electronic products
of all types (kiosks, ATMs, cell phones, USPS automated postal stations and
For other Trace Center work on voting see www.trace.wisc.edu/voting
to the NIST HAVA Website
policy / security notice / accessibility statement
Disclaimer / FOIA
NIST is an agency of the U.S. Commerce Department
Last updated: July 24, 2007
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