... Their feedback is that the ballots in prior revisions
would have these errors every 5 ballots or so. Now we are up to
every 20 to 30 or so, depending on... what I don't know. I guess
my question is: Is this related to strictly a software issue, or
is there some tolerance level of mark on the ballot we're coming up
against? Is this in the physical world of the ballot or in the
software or both??
I was hoping that
someone else would address this but here goes.
The ballot scanning error rate is affected by many factors
including:
- the firmware's timing mark filtering algorithms,
- the firmware's
scan data processing algorithms,
- the scanner's processing of the
sensor inputs (remember that the Lucid visible light readers have their own
processors),
- the optical and electrical characteristics of the
sensors,
- the operating voltages and electrical noise,
- the
relative and absolute speeds of the scanner and feeder motors,
- the
ballot paper stock,
- the cut of the ballots,
- the printing ink,
- the tolerances of the printing of the ballot marks,
- the
complexity of the ballots (number of voting positions, complexity of voting
rules, etc. which affects timing),
- and probably a few other factors
that don't come to mind right now.
The Accu-Vote's firmware is the easiest thing to change and we do
the best that we can with the information that it receives from the scanner
boards. We probably could do better in particular cases but it's a
difficult problem with many tradeoffs for every parameter that we have to
work with. It is likely that most of your errors are a problem in
interpreting the data that the Accu-Vote gets when the ballots coming from
the feeder are moving faster than the normal speed of the Accu-Vote. The
ballot experiences a sudden deceleration and the resulting scan data is
difficult to interpret. It could also be that the feeders are slipping
to a variable degree and when they don't slip, they deliver the ballot
before the Accu-Vote is ready to scan it. It could also be that some
of your ballots take longer to process than others and again the next ballot
could arrive before the AV is ready. There's many possibilities.
Thus if you'd like us to comment on your particular situation,
send us a sample test deck and database to work with because the entire
process is quite sensative to all the ballot parameters. We'll then
work from there and try to identify the sources of the scanning
errors. Otherwise be assured that the AV runs many cross checks on the
data and only accepts a ballot when the scan data can be interpreted
correctly.
Guy