Ballot Information File (bif) Report (Metadata Report)

2023 November Municipal, Rockville City, MD

Audit Engine version:'v2.32.X'

Run Date: 2026-09-09 13:57:47.274762 Copyright (c) Citizens' Oversight


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Ballot Metadata Report Introduction

This report is a reconciliation of all metadata captured from various sources. The number of sources included may vary, based on the workflow and availability of image archives and the CVR. This report is essential when performing public oversight workflow audits, because it allows audit conductors to examine metadata to understand ballot style assignments, repeated ballots by ballot_id and repeated images, and to compare across all sources, images, CVR and any aggregated results. Each section of this report will have a separate introductory paragraph.

Table of Contents

High Level Reconciliation

parameter images cvrs images-cvrs results results-images
num_files 1 1 0 0 0
raw_total 12,637 12,637 0 0 -12,637
repeated ballot_ids 0 0 0 0 0
net unique ballot_ids 12,637 12,637 0 0 -12,637
net unique BMD Ballots 0 0 0 0 0
repeated sheets 0 0 0 0 0
repeated BMD Ballots 0 0 0 0 0
repeated nonBMD Ballots 0 0 0 0 0
repeated residue 0 0 0 0 0
net unique sheets 12,637 12,637 0 0 -12,637
net unique sheets in common 12,637 12,637 0 0 0
net unique sheets not in common 0 0 0 0 0

Metadata Summary

Parameter Value
Election Name 2023 November Municipal, Rockville City, MD
Official Ballots Cast 0
Number of precincts 10
Number of parties 1
Number of contests 6
Number of styles 10
Number of hexstyles (patterns of contests) 1
Number of BMD ballots 0
Number of different sheets 0
---- Ballot Image Archives (BIAs) ---- --------------------
Number of BIA Ballot Archives 1
Unique ballot_ids in BIAs 12,637
Total number of records in BIAs 12,637
Num. kept repeated ballot_ids in BIAs 0
Num. skipped repeated ballot_ids in BIAs 0
Num. skipped repeated images 0
BIA_num (unique images) 12,637
cast_num == BIA_num? False
ballots cast > BIA by 0
ballots in BIA > cast by 12,637
---- Cast Vote Records (CVRs) ---- --------------------
Number of CVR files 1
Unique ballot_ids in CVRs 12,637
Total number of CVR records 12,637
Number of repeated CVR ballot_ids 0
ballotids in CVR == BIA? True
---- Metadata from Images (BLTs) ---- --------------------
BLT_unique_ballots_num 12,637
Total number of BLT bif records 12,637
Duplicate BLT ballot_ids 0
ballotids in BLT == BIA? False
ballotids in BIA not in BLT 0
ballotids in BLT not in BIA 0
ballots cast not in BLT -12,637
Number of card_codes 11
Number of ballots with no card_codes 0
Number of corrupted ballots 199

Card code to style_num analysis (conv_card_code_to_style_num)

This report summarizes the mapping of style numbers to the card_codes, hexstyles, and precincts. There should be a one-to-one mapping for each. This table is for nonBMD ballots only.

Field Description
style_num This value identifies a style
Card Code This is the actual bit sequence on the ballot which is converted to the style_num
Count The number of ballot sheets with this style
hexstyles The mapping of contests on this style. There should be only one item in the list.
precinct There is usually only one style in one precinct, but there may be multiple precincts with a single style
style_num Card Code Count hexstyles precinct ballot_id samples
3 0x3100f008 734 ['0xfc'] ['3'] ['10571', '10608', '10625']
9 0x3100e420 995 ['0xfc'] ['9'] ['1797', '1821', '1824']
10 0x3100e410 1663 ['0xfc'] ['10'] ['1241', '1256', '1281']
8 0x3100e804 1156 ['0xfc'] ['8'] ['8705', '8708', '8709']
2 0x3100f010 2448 ['0xfc'] ['2'] ['2135', '2142', '2144']
4 0x3100f004 917 ['0xfc'] ['4'] ['3980', '3982', '3989']
1 0x3100f020 1128 ['0xfc'] ['1'] ['3863', '3865', '3873']
5 0x3100e820 1004 ['0xfc'] ['5'] ['11566', '11570', '11571']
6 0x3100e810 866 ['0xfc'] ['6'] ['21', '28', '54']
7 0x3100e808 1527 ['0xfc'] ['7'] ['8919', '8920', '8927']

Small Styles Report

This report provides an analysis of the number of ballots that are included in "small styles" and therefore, there is a threat that the voter could be linked to their ballot. For purposes of this analysis, a "Small Style" is defined as a style with fewer than k ballots in it. The worst case is if there is only one ballot in the small style, because that voter could be linked to their ballot if other information were cross-references with the cast vote record data. AuditEngine explicitly does not link voters to their ballots.

Very commonly, the reason for small styles is due to handling the federal-only ballots, which tend to be UOCAVA (Uniformed And Overseas Citizens Absentee Voting Act) voters. The privacy of these ballots can be easily improved by NOT splitting them by precinct, but instead by including them in one large virtual precinct.

Summary for unified table

District Type Total Ballots Small Styles Split Styles Ballots % in Small Styles Unsplit Small Styles Unsplit Ballots % Affected
US_MD_Rockvillecity_20231107_ocrmapped 2023 November Municipal 12,438 0 0 0 0.0000% 0 0 0.0000%

Small Styles

{closing}

Hexstyle to style_num analysis (use_hexstyle_as_cvr_style)

This report is another way to look at the styles in the election. The 'hexstyle' value is a description of the contests in the election. Each row in this table is a unique set of contests on the ballot. Sometimes, if the same set of contests is applicable to more than one precinct, a style will be defined for each precinct. Voter privacy can be improved by combining precincts that have the same set of contests if the "ballots" field is low.

hexstyle ballots example num_styles styles_nums num_prec precincts (first 10) nonBMD filesize mean nonBMD filesize stdev num BMDs
0xfc 12438 10571 10 ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10'] 10 ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10'] 75998.81476121563 506 0

Summary Report by precinct

precinct num_ballot_ids num_BMDs num_nonBMDs w/cvr w/image archive_basename(s) style_num hexstyles card_codes
3 734 0 734 734 734 MD_Rockville 2023-All Ballots.zip 3 0xfc 0x3100f008
9 995 0 995 995 995 MD_Rockville 2023-All Ballots.zip 9 0xfc 0x3100e420
10 1663 0 1663 1663 1663 MD_Rockville 2023-All Ballots.zip 10 0xfc 0x3100e410
8 1156 0 1156 1156 1156 MD_Rockville 2023-All Ballots.zip 8 0xfc 0x3100e804
2 2448 0 2448 2448 2448 MD_Rockville 2023-All Ballots.zip 2 0xfc 0x3100f010
4 917 0 917 917 917 MD_Rockville 2023-All Ballots.zip 4 0xfc 0x3100f004
1 1128 0 1128 1128 1128 MD_Rockville 2023-All Ballots.zip 1 0xfc 0x3100f020
5 1004 0 1004 1004 1004 MD_Rockville 2023-All Ballots.zip 5 0xfc 0x3100e820
6 866 0 866 866 866 MD_Rockville 2023-All Ballots.zip 6 0xfc 0x3100e810
7 1527 0 1527 1527 1527 MD_Rockville 2023-All Ballots.zip 7 0xfc 0x3100e808

This report simply provides a list of the mapping from the field specified to the styles.

Summary Report by batchid

batchid num_ballot_ids num_BMDs num_nonBMDs w/cvr w/image archive_basename(s) style_num hexstyles card_codes
12438 0 12438 12438 12438 MD_Rockville 2023-All Ballots.zip 1 10 2 3 4 5 6 7 8 9 0xfc 0x3100f008 0x3100e420 0x3100e410 0x3100e804 0x3100f010 0x3100f004 0x3100f020 0x3100e820 0x3100e810 0x3100e808

This report simply provides a list of the mapping from the field specified to the styles.

Ballots with alignment errors or unreadable barcodes

When the ballot images are initially examined to capture the style number, there are usually a few that are distorted typically due to slipping in the scanner, or there may be damage to the barcode area where the style number is expressed. These should be included as "ballot variants" in the comparison report, and if for close elections, it may be necessary to capture these by human-eye and manual entry using the AdjudiTally app. When this table indicates that there is a "Cardcode lookup error" or "no Card Codes read", this typically is due to image distortion.

First 50 of 199:

ballot_id archive_basename style_num error_details
8996 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10730 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10735 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10738 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10741 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11043 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12171 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12230 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12437 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12587 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10731 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10732 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10733 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10740 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10744 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
10745 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11042 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11293 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11324 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11328 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11331 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11332 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11425 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11429 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11433 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11434 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11436 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11541 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11841 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12085 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12137 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12141 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12431 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12433 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12583 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12584 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12585 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
9796 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12091 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12187 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12188 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12220 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12225 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12235 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12292 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12586 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11435 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
11442 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12087 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num
12138 MD_Rockville 2023-All Ballots.zip models/Ballot.py:2063 Unable to resolve style_num

Introduction

This report details information about the ballot image archives provided by the election district. These ballot image archives are typically provided as ZIP archives, but they may also be PDF files with many 1000s of images of sheets in some cases. Here, we review the sizes of the images and whether there are any repeated ballot_ids. This does not examine the images to find repeats, but simply marks them as repeats if they have the same ballot_id. The ballot_id of each ballot sheet must be unique. If there are multiple-sheet ballots, they will have multiple images that are not kept together.

Ballot Image Archives Summary

Parameter Value
Raw Number of Files 12,637
Unique ballot_ids 12,637
num_skipped_dups 0
num precincts 10
Number of parties 1
Number of groups 1
Number of batchids 0
Number of BMD ballots detected 199
Largest ballot image (bytes) 89,788
Smallest ballot image (bytes) 13,536
Number of huge files (> 6 * sigma) 0
idx archive basename files image_files all ballotids num uniques within set repeats num prior repeats num skipped repeats num BMDs num precincts num parties num groups num batchids lowest ballotid highest ballotid
0 'MD_Rockville 2023-All Ballots.zip' 12,637 12,637 12,637 12,637 0 0 0 199 10 1 1 0 1 12,637
12,637 12,637 12,637 12,637 0 0 0 199 0
idx archive basename all ballotids unique within set repeats prior repeats total skipped repeats
0 MD_Rockville 2023-All Ballots.zip 12637 12637 0 0 0

Ballot Image File Size Extremes

ballot_id size (bytes)
12,281 13,536
5,749 89,788

End of Ballot Information File (bif) Report

2023 November Municipal, Rockville City, MD

Audit Engine version:'v2.32.X'

Run Date: 2026-09-09 13:57:49.512975 Copyright (c) Citizens' Oversight


Return to Master Report Index