Glossary

Air-Gapped Tabulation System

A physical security architecture requirement in which election equipment and tabulation computers are permanently isolated from public networks, local area networks, and wireless hardware.

Droop Quota

The standard mathematical formula used in multi-winner proportional Ranked Choice Voting to calculate the minimum number of votes required for a candidate to secure a seat:

Winning Threshold = (Total Valid Active Votes) divided by ([Number of Seats + 1] + 1)

Duplicate Ranking

A ballot marking pattern where a voter ranks the same candidate across multiple columns (e.g., marking Candidate A as 1st, 2nd, and 3rd choice). Tabulation rules count the highest rank awarded to that candidate and ignore identical subsequent rankings.

Exhausted Ballot

A ballot that can no longer be transferred during round-by-round RCV tabulation because every candidate ranked on the ballot has either already been elected or eliminated from the contest.

Majority Threshold

The minimum vote share required to win a single-seat RCV contest, defined as more than 50% of valid active votes cast in that tabulation round:

Majority Threshold = (Total Valid Active Votes divided by 2) + 1

Multi-Winner Ranked Choice Voting (Single Transferable Vote / STV)

A proportional electoral system used in multi-seat districts (such as Portland City Council elections) where voters rank candidates by preference. Candidates who meet or exceed a set threshold of votes are elected. Surplus votes from elected candidates and votes from eliminated candidates transfer to voters' subsequent preferences to ensure legislative bodies reflect the proportional vote share of the electorate.

Overvote

A ballot marking error where a voter selects multiple candidates within the same ranking column (e.g., selecting two candidates as 1st choice). An overvote invalidates that specific ranking column, causing tabulation to skip to the voter's next valid ranking in subsequent columns.

Plurality Voting (First-Past-the-Post)

An electoral system in which the candidate who receives the highest total number of votes wins, regardless of whether they achieve an absolute majority (over 50%) of the total votes cast.

Proportional Representation

An electoral principle establishing that political bodies should mirror the proportional division of the electorate. Under proportional systems, a group or political bloc controlling a specific percentage of votes wins a roughly equivalent percentage of seats.

Risk-Limiting Audit (RLA)

A post-election statistical quality control procedure where physical paper ballots are manually hand-counted in random samples to mathematically verify that the machine-tabulated election winner matches the true outcome of the physical paper ballots.

Single-Winner Ranked Choice Voting (Instant-Runoff Voting / IRV)

An electoral process for single-seat offices where voters rank candidates in order of preference (1st choice, 2nd choice, 3rd choice, etc.). If no candidate receives a majority (over 50%) of first-choice votes, the candidate with the fewest votes is eliminated. The votes of supporters of the eliminated candidate automatically transfer to those voters' next-ranked active choice. Tabulation continues until one candidate commands a majority.

Skipped Ranking

A ballot marking pattern where a voter leaves an intermediate ranking column blank (e.g., marking a 1st choice and 3rd choice while leaving 2nd choice blank). Automated tabulation systems ignore the empty rank and advance the next valid preference (3rd choice) to fill the skipped position.

Surplus Fractional Transfer

A tabulation procedure in multi-winner proportional RCV where candidate votes exceeding the winning threshold (quota) are transferred to next-ranked choices at a fractional value calculated as:

(Total Votes Received - Winning Quota) divided by (Total Votes Received)

Transfer Round

A discrete step during RCV vote counting where votes are reallocated either from an eliminated lowest-vote candidate or from an elected candidate who exceeded the winning threshold.

Undervote

An instance where a voter chooses not to fill out all available ranking columns on an RCV ballot, or leaves a given ballot contest entirely blank.