Trusted Logic Voting (TLV)

One consistent thread in the testing and certification of touch screen devices is their calibration and alignment.

Where the operator sees their finger touched the screen and the underlaying text should be the same as where the computer thinks they have also touched. The two should be corresponding.

Unfortunately this is a mechanical and electrical alignment. The computer has no way of knowing if its calibration is skewed. Any kind of physical shock damage or electrical field misalignment can cause the computer to get it wrong. Shipping devices to polling stations is of course exactly when this can occur.

Small misalignments can be very confusing to human operators - where they consistently re-try to get the computer to accept their choice - not realizing that they need to touch a slightly different area of the screen instead.

Pennsylvania has opted to de-certifed their Unilect Patriot voting machines for exactly this reason - lack of consistency and reliable operation. Instead the counties effected will rely on their paper-based ballot scanning systems.

http://pittsburghlive.com/x/tribune-review/trib/regional/s_327234.html

and

http://www.post-gazette.com/pg/05113/493123.stm

and

http://portland.indymedia.org/en/2005/04/316574.shtml

Once again we are seeing that the rush to adopt DREs as the solution to meet HAVA requirements is being blunted by practical considerations and a realization that the technology is not yet ready nor mature enough to meet the rigours of real-world operaton beyond the lab'.