Statistical Analysis of the Post-Election Audit Data 2010 August Primary Election

The Center for Voting Technology Research (VoTeR Center) at the School of Engineering of the University of Connecticut received the data gathered in the post-election audit performed in the State of Connecticut following the August 2010 primary election. The audits involved the randomly selected 10% of the districts and the audit returns were conveyed by the Office of the Secretary of the State (SOTS) to the VoTeR Center from September 21st (almost all returns) to October 26th of 2010. The audit data received by the VoTeR Center contains 465 records, where each record represents information about a given candidate: date, district, machine seal number, office, candidate, machine counted total, hand counted total of the votes considered unquestionable by the auditors, hand counted total of the votes considered questionable by the auditors, and the hand counted total, that is, the sum of undisputed and questionable ballots. The review of the audit reports prepared by the towns did not reveal any returns with high unexplained differences between hand and machine counts. The largest discrepancy is a single case of 6 votes (4.5%), the second largest is a single case of 4 votes (0.99%). The rest show discrepancies of one or less, with 95.7% of the returns showing no discrepancies. There are in total twenty records with discrepancies. We note that in seven cases out of twenty the auditors provided an explanation for the observed discrepancies. Majority of the explicated cases refer to the improper markings of the ballots by voters. One of the examples of such an improper marking is having ‘X’ mark in the bubble instead of filling in the bubble. The optical scan machine used in Connecticut, the AccuVote optical scanner, is able to recognize partially marked bubbles in some cases, but this depends on the bubble fill pattern. This report presents the analysis of the submitted audit returns. No records were found to be incomplete, unusable, or obviously incorrect; this is a substantial improvement. Among 465 (100%) records there are 445 (95.7%) records showing no discrepancy, 18 records (3.9%) show discrepancy of 1 vote, and 2 records (0.4%) show discrepancy of 4 and 6 votes between the machine counts and audit hand counts. The maximum number of discrepancies is 6 votes. The data presented in this analysis show that the average reported discrepancy is much lower than the number of questionable ballots (0.06 versus 1). Moreover, for the majority of the records (70%) showing discrepancy, the number of questionably marked ballots (as determined by the human auditors) is greater than the reported discrepancy. This analysis was performed on request of the Office of the Secretary of the State.

Full report: 2010-aug-hand-v11

This entry was posted in news.