Re: Voting System Standards

From: Dennis Paull <dpaull_at_svpal_dot_org>
Date: Sun Jul 27 2003 - 20:46:34 CDT

Alan, your analysis needs some expansion.

What are you comparing to what? Comparing the internal tally against
the ballot images proves nothing. You need to compare to the paper
ballots to be meaningful. Normally, to select a truly random sample,
you would need to first enter (scan) all the ballots and let the
computer select the random sample. But we also want to keep all the
ballots from each precinct together for later recounts. So we don't
want to hand select the sample.

As soon as you agree that all the ballots will be scanned, you can
also say that the electronic tally is preliminary and that the
scanned ballots are the only true count. If no funny-business is
found, the numbers will be the same except for absentees, writeins
and provisionals. However, absentees ballots are gaining higher
usage. Early absentee ballots are pre-qualified and then counted as
soon as the polls close (or sooner). Absentees turned in at the
polling place need to be qualified and then counted, which can take
many days. So the official count is delayed in any case.

Typically, I think, the elections office has a scanner that is at
least ten times faster than the scanners in the precinct, if any.
These are much more expensive, but you only need one or two per
county. They are needed for absentee and provisional ballots
anyway, so there is no additional expense.

I recommend the scan all ballots for the official tally technique.

Dennis Paull

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
At 04:47 PM 7/27/2003 Sunday , you wrote:
>From: "Douglas W. Jones" <jones@cs.uiowa.edu>
>>
>> Indeed, your system, and for that matter, the Populex system and the
>> Avante system, both of which print "receipts" that serve, legally,
>> as ballots, are not, strictly speaking, DRE systems.
>>
>Since ours is not a DRE, strictly speaking, it might be worthwhile to
>discuss some about the relationship of the electronic record to the paper
>ballots. Here's what I think.
>
>The paper ballot represents the authentic vote in this system. But the
>electronic record is valuable for two main reasons:
>
>1) Faciltates tabulation of the vote
>2) Serves as additional security against several forms of attack (for
>example, ballot box stuffing, counterfeit ballots, swapping ballots,
>destroying ballots, rigged scanners).
>
>FACILITATION OF VOTE TABULATION
>-----------------------------------------------
>The electronic record could be used to give a very quick but accurate
>election result. Once the files are transferred from the precinct to the
>county headquarters, tabulation should take seconds. But this will be the
>preliminary unofficial unaudited tally. We can get a very good idea of the
>winners by sampling the paper ballots.
>
>We can use binomial distribution to do the calculations. I have a
>calculator that a fellow by the name of Bill Buck helped me with. It's in
>Excel and uses the BINOMDIST function in Excel. I am trying to get someone
>else to write a standalone calculator. Anyway, if you have Excel you can
>try it out here:
>
>http://home.earthlink.net/~adechert/LOTAcceptanceCalculator.xls
>
>In this case, the sample is accepted if no defects are found -- rejected if
>one is found. So, the "defects found in sample" will have to be zero.
>
>For example, suppose in a two way race candidate A got 505,000 votes and
>candidate B got 495,000 according to the electronic record. Let's say, for
>now, that if we compute a 99.999 percent confidence level, we can safely
>announce candidate A as the winner (with 99.999, we'll be wrong once in
>100,000 contests). The outcome could only be wrong if 5,000 votes turn out
>to be taken away from A or added to B. This is a fraction of .005 of the
>million votes cast. If we enter .005 in the LOT FRACTION DEFECTIVE cell
>along with 1,000,000 in the "Election Size" field and play with the required
>sample size, we can find a number that will give us the 99.999 Confidence
>Level we want. A few tries and I get .99999 with 2,300 samples. So with
>this in mind, we know if we can collect a random sample of 2,300 ballots and
>check them against the electronic record (and the match), we are 99.999
>percent certain that Candidate A won. This sample could be obtained pretty
>quickly. A fuller audit can be performed later. In practice, samples will
>usually be much smaller since races are usually won or lost by several
>percent -- not so close as this example. For example, you only need a
>sample of 550 ballots where a 2.5 percent swing could change the outcome.
>
>If everyone follows procedures, there should not be any mismatches. Even if
>a defect is found (for example, a paper ballot that has no corresponding
>record in the electronic table of ballot images), it won't necessarily
>disturb the outcome -- it will just take a little longer. You just take a
>larger sample until you reach the desired confidence level. If more than a
>few defects are showing up, we may have to scan all the ballots. Again,
>this might delay the result slightly but still should be done fairly
>quickly. We can then also do hand sampling of the scanned result for
>further verification.
>
>It may be that all the ballots will be scanned as the election is audited in
>the days after Election Day.
>******
>more on this later.
>
>Alan
>
Received on Sun, 27 Jul 2003 18:46:34 -0700

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