Checking election outcome accuracy Post-election audit sampling

Abstract

This article * provides an overview of post-election audit sampling research and compares various approaches to calculating post-election audit sample sizes, focusing on risklimiting audits, * discusses fundamental concepts common to all risk-limiting post-election audits, presenting new margin error bounds, sampling weights and sampling probabilities that improve upon existing approaches and work for any size audit unit and for single or multi-winner election contests, * provides two new simple formulas for estimating post-election audit sample sizes in cases when detailed data, expertise, or tools are not available, * summarizes four improved methods for calculating risk-limiting election audit sample sizes, showing how to apply precise margin error bounds to improve the accuracy and efficacy of existing methods, and * discusses sampling mistakes that reduce post-election audit effectiveness.