# Implementing Risk-Limiting Post-Election Audits in California

@article{Hall2009ImplementingRP, title={Implementing Risk-Limiting Post-Election Audits in California}, author={Joseph Lorenzo Hall and Philip B. Stark and Luke Miratrix and Melvin Briones and Elaine Ginnold and Freddie Oakley and Martin Peaden and Gail Pellerin and Tom Stanionis and Tricia Webber}, journal={LSN: Law \& Economics: Public Law (Topic)}, year={2009} }

Risk-limiting postelection audits limit the chance of certifying an electoral outcome if the outcome is not what a full hand count would show. Building on previous work [18, 17, 20, 21, 11], we report pilot risk-limiting audits in four elections during 2008 in three California counties: one during the February 2008 Primary Election in Marin County and three during the November 2008 General Elections in Marin, Santa Cruz and Yolo Counties. We explain what makes an audit risk-limiting and how…

## 40 Citations

Efficient Post-Election Audits of Multiple Contests: 2009 California Tests

- Computer Science
- 2009

Three refinements to increase efficiency were tested in Marin and Yolo counties, California, in November 2009, and all three can be used together, resulting in extremely efficient risk-limiting audits.

Risk-Limiting Audits for IRV Elections

- MathematicsArXiv
- 2019

A number of approaches to ballot-polling and comparison risk-limiting audits for Instant Runoff Voting (IRV) elections are defined and it is shown that for almost all real elections, one can perform a risk- Limiting audit by looking at only a small fraction of the total ballots.

RAIRE: Risk-Limiting Audits for IRV Elections.

- Mathematics
- 2019

Risk-limiting post election audits guarantee a high probability of correcting incorrect election results, independent of why the result was incorrect. Ballot-polling audits select ballots at random…

Random Manual Risk-limiting Post-election Audits

- BusinessSSRN Electronic Journal
- 2019

This article presents post-election audits designed to limit the risk of certifying an incorrect election outcome to any desired low probability, say α = 0.05. Its contributions are to: provide…

Risk-Limiting Postelection Audits: Conservative $P$-Values From Common Probability Inequalities

- MathematicsIEEE Transactions on Information Forensics and Security
- 2009

This paper gives simple approaches to calculating a conservative P-value for several ways of summarizing overstatements andSeveral ways of drawing the sample of batches to audit, emphasizing sampling with probability proportional to a bound up on the error in the pth audit batch (PPEB sampling).

BRAVO: Ballot-polling Risk-limiting Audits to Verify Outcomes

- BusinessEVT/WOTE
- 2012

BRAVO is described, a flexible protocol for risk-limiting ballot-polling audits that can improve election integrity immediately at nominal incremental cost to election administration.

Workload Estimates for Risk-Limiting Audits of Large Contests

- Computer Science
- 2011

This work compares the expected number of ballots that must be counted by hand for two risk-limiting auditing methods, Canvass Audits by Sampling and Testing and Kaplan-Markov, and discusses several methods to reduce batch sizes using current vote tabulation systems.

Election Audits Using a Trinomial Bound

- MathematicsIEEE Transactions on Information Forensics and Security
- 2009

The trinomial confidence bound confirmed the results without a full count, even though the Santa Cruz audit found some errors, and gave better results than the Stringer bound, which is commonly used to analyze financial audit samples drawn with probability proportional to error bounds.

Enabling More Meaningful Post-Election Investigations

- Computer Science
- 2010

A novel approach for logging events in direct recording electronic (DRE) voting systems, and a novel process for efficiently verifying elections that use optical scan voting systems are described.

Risk-limiting Audits: A Practical Systematization of Knowledge

- Computer Science
- 2021

A review of existing RLA techniques is presented, providing a concise definition of an RLA, examining its underlying assumptions, and discussing how RLAs work in practice are discussed, all from the perspective of the maintainer of a popular RLA tool.

## References

SHOWING 1-10 OF 56 REFERENCES

Efficient Post-Election Audits of Multiple Contests: 2009 California Tests

- Computer Science
- 2009

Three refinements to increase efficiency were tested in Marin and Yolo counties, California, in November 2009, and all three can be used together, resulting in extremely efficient risk-limiting audits.

Risk-Limiting Postelection Audits: Conservative $P$-Values From Common Probability Inequalities

- MathematicsIEEE Transactions on Information Forensics and Security
- 2009

This paper gives simple approaches to calculating a conservative P-value for several ways of summarizing overstatements andSeveral ways of drawing the sample of batches to audit, emphasizing sampling with probability proportional to a bound up on the error in the pth audit batch (PPEB sampling).

Election Audits Using a Trinomial Bound

- MathematicsIEEE Transactions on Information Forensics and Security
- 2009

The trinomial confidence bound confirmed the results without a full count, even though the Santa Cruz audit found some errors, and gave better results than the Stringer bound, which is commonly used to analyze financial audit samples drawn with probability proportional to error bounds.

A Sharper discrepancy measure for post-election audits

- Economics
- 2008

Post-election audits use the discrepancy between machine counts and a hand tally of votes in a random sample of precincts to infer whether error affected the electoral outcome. The maximum relative…

CAST: Canvass Audits by Sampling and Testing

- Computer ScienceIEEE Transactions on Information Forensics and Security
- 2009

Canvass audit by sampling and testing (CAST) is a method to decide on the basis of a hand count of a random sample of batches of ballots whether to count the entire audit trail of a contest by hand.…

Machine-Assisted Election Auditing

- BusinessEVT
- 2007

It is shown how to determine which ballots to audit against the recounting machines' records and compared to precinct-based audits in the context of Virginia's November 2006 election, and extensions to these techniques that promise further efficiency gains are explored.

Conservative statistical post-election audits

- Economics
- 2008

There are many sources of error in counting votes: the apparent winner might not be the rightful winner. Hand tallies of the votes in a random sample of precincts can be used to test the hypothesis…

On Auditing Elections When Precincts Have Different Sizes

- Computer ScienceEVT
- 2008

Experimental results are given showing that NEGEXP and PPEBWR can dramatically reduce the cost of auditing compared to methods such as SAFE that depend on the use of uniform sampling.

Auditing a collection of races simultaneously

- Computer Science
- 2009

A collection of races in a single election can be audited as a group by auditing a random sample of batches of ballots and combining observed discrepancies in the races represented in those batches…

Election Certification by Statistical Audit of Voter-Verified Paper Ballots

- Computer Science
- 2004

This paper analyzes two election audit processes: a conventional statistical recount, and a statistical error count that detects discrepancies between ballot database records and corresponding paper ballots that would have enormous advantages of efficiency and robustness.