Statistical Analysis of the Post-Election Audit Data 2010 November 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 November 2010 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 on December 22nd of 2010. The audit data received by the VoTeR Center contains 867 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. This report contains several statistical analyses of the audit returns and recommendations. The statistical analysis in this report deals with the 847 records that are sufficiently complete to perform the analysis. The VoTeR Center’s initial review of audit reports prepared by the towns revealed a number of returns with unexplained differences between hand and machine counts. The vast majority of records with high discrepancies were concentrated in the following three districts: East Haven (Deer Run School) with the highest reported discrepancy of 180, Hartford (Burns School) with the highest reported discrepancy of 170, and Preston (Town Hall) with the highest reported discrepancy of 55. Additionally, one or more discrepancies were reported in all but one district for the town of Orange; here the highest reported discrepancy was 14, however this could not be explained as no questionable ballots were reported. Following this initial review the SOTS Office performed additional information gathering and investigation and, in some cases, conducted independent hand-counting of ballots in the four districts mentioned above. The final information was conveyed to the VoTeR Center on June 17th of 2011 for the 48 records pertaining to those districts. The rest of the records (799 out of 847) discussed in this audit report are the original records reported by the towns. This report presents the analysis of 847 records (97.7%), among which 799 records (94.3%) are from the original data and 48 records (5.7%) were revised based on the follow up conducted by the SOTS office. For the revised records the discrepancy was reduced to 0 for 38 records (79.2%), the remaining 10 records indicate a discrepancy of either 1 vote (10.4% of the revised records) or 2 votes (10.4% of the revised records). Among 847 (100%) records there are 485 (57.3%) records showing no discrepancy, 132 records (15.6%) showing discrepancy of 1 vote, 187 records (22.1%) showing discrepancy of 2 to 5 votes, 42 records (4.9%) showing discrepancy of 6 to 13 votes (for this group, although no manual review of the discrepancies was conducted, the SOTS Office affirmed that the discrepancies were due to hand counting errors), and 1 record (0.1%) showing discrepancy of 25 votes. The last discrepancy of 25 votes belongs to a cross-party endorsed candidate. The SOTS Office confirmed that this discrepancy was due to misallocation of correctly counted votes to different party totals. The data presented in this analysis show that the average reported discrepancy is lower than the number of questionable ballots (1.26 versus 1.54). This analysis was performed on request of the Office of the Secretary of the State.

Full report: 2010-Nov-Hand-V12


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