Percentage-Based versus Statistical-Power-Based Vote Tabulation Audits

[Wilms]

"Tiered percentage audits specify a percentage of precincts to be audited, depending on the reported winning margin."

"This approach addresses the need to audit more when margins are narrower..."

"Statisticians and a growing number of election experts have urged replacing fixed percentage audits with audits that employ a statistically grounded criterion of efficacy. Here we present a power-based audit which determines the number of precincts that must be sampled to achieve a specified power level for each election contest. In addition to the desired power, the sample size will depend on the reported victory margin, the value ofWPM, and both the number and size-distribution of the precincts."

"Since a key purpose of a post-election vote tabulation audit is to provide a check on the original tabulations, procedures should verify election results without trusting any part of the software used in voting."

Percentage-Based versus Statistical-Power-Based Vote Tabulation Audits

Authors: McCarthy, John; Stanislevic, Howard; Lindeman, Mark; Ash, Arlene S.; Addona, Vittorio; Batcher, Mary
Source: The American Statistician, Volume 62, Number 1, February 2008 , pp. 11-16(6)
Publisher: American Statistical Association



Abstract:

Several pending federal and state electoral-integrity bills specify hand audits of 1% to 10% of all precincts.

However, percentage-based audits are usually inefficient, because they require large samples for large jurisdictions, even though the sample needed to achieve good accuracy is much more affected by the closeness of the contest than population size. Percentage-based audits can also be ineffective, since close contests may require auditing a large fraction of the total to provide confidence in the outcome.

We present a plausible statistical frame-work that we have used in advising state and local election officials and legislators. In recent federal elections, this audit model would have required approximately the same effort and resources as the less effective percentage-based audits now being considered.

http://www.ingentaconnect.com/content/asa/tas/2008/00000062/00000001/art00002


A free full text pdf version is available:
pdf: http://verifiedvoting.org/downloads/TAS_paper.pdf

[Peace Patriot]

1. Good idea--if we have to put up wth 'TRADE SECRET,' PROPRIETARY vote counting code,

with the code owned and controlled by rightwing Republican corporations.

Can't be too careful.

Sorry. I feel a bit nasty-ironical-cynical today.

Here's my assessment of California's election integrity, and prognosis on the reliability of the results on Feb 5, even with our new reforming SoS. This assessment has a lot of tools to help folks analyze the returns (inclu where to look for problems).

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=203x496552

[Peace Patriot]

2. Our new SoS is doing 10% when margin is 0.5% or less, and

escalated auditing when the standard 1% turns up anomalous results. She's also requiring VVPAT for all touchscreens (now in limited use in CA).

But the pisser is that San Diego, Riverside and San Bernardino Counties--all deep into the rightwing corporate vendors' pockets--SUED SoS Bowen to stop these reforms. They lost, but it's a good indicator of their BAD ATTITUDE, which affects election integrity in many other ways. San Diego took the lead in the legal assault on these minimal reforms. SD registrar is Deborah Seiler, who used to be chief Diebold salesperson in Calif. (SD has a Diebold system.) And that is so unbelievably corrupt you gotta wonder if the deep, dark Republican establishment in SD feels any responsibility at all to the people of the county.

CA has too many of these corrupt kind of county registrars, who owe their allegiance to the corporate vendors, not to the voters--and this very much influenced my assessment of CA's election integrity. What if they drive this reformer SoS out of office, the way they did Kevin Shelley (after he sued Diebold for fraud in '04)? What if they sabotage her reforms? What if they mess up the Feb 5 election to get her out? They're perfectly capable of it.

And their little legal tizzy with taxpayers' money was over an up-to-10% audit, in special circumstances, which is not nearly enough.

[Wilms]

3. I know you aren't surprised. But for others who may not be aware...

[Peace Patriot]

5. It's mind-boggling, aint't it? nt

[Bill Bored]

6. Actually, Peach Patriot...

...Bowen, as a condition of recertification of all those decertified voting systems (including optical scan), required much more rigorous auditing of vote counts, similar to that recommended in the paper in the OP.

Now, either Bowen overstepped her bounds, or the RoV's have more power than she does, or the citizens of California are far too complacent in not demanding that she, and the RoVs implement her directives. All three are possible in fact.

The problem is: Auditing is boring. And solutions are not as sexy or as interesting as problems. Once the DREs were almost totally banned in CA, I imagine a lot of folks lost interest in the electronic vote-counting issue. After all, there's a paper ballot -- what can go wrong?

Bowen and her team clearly tried to do the right thing.

The question is: Why are they not following through with the auditing requirements set forth by the Post-Election Audit Standards Working Group and the Withdrawals of Approval and Conditional Re-approvals of California's voting systems?

If RoVs are suing the SoS, why aren't citizens suing them both at this point to see that these directives are implemented? Just a thought.

[Stevepol]

4. K&R!