A PEA for proof.

• Author: Underhill, Wendy
• Position: TRENDS & TRANSITIONS - Post-election audits

Call it a post-election review, evaluation, inspection, analysis or audit--the label doesn't matter. But elections results do. No surprise, then, that officials, candidates and citizens want to make sure voting equipment and procedures are working reliably.

Recounting every ballot is one way to check, but that's expensive and unnecessary in all but the closest of races. Instead, 25 states and the District of Columbia use "post-election audits (PEAs)." During a typical PEA, election officials examine ballots from randomly selected precincts or machines, retally the results by hand, and compare that result to what was reported on election night. Every so often, the process turns up a programming error or equipment malfunction.

State-by-state details on post-election audits vary considerably. In Michigan, which enacted its first audit requirement this year, the word "audit" refers to a procedural check: Did each polling place operate according to law? "The sanctity of the ballot is vitally important," says Representative Anthony Forlini (R), the bill's sponsor. "If there's any degree of uncertainty, people are going to say, 'Why are we voting?' This way, we know that everyone's got a fair shot."

Other states, such as California and Colorado, are piloting new "risk-limiting audits," using statistical techniques that provide greater certainty that the results are correct but require far...