Additional-member systemThe additional-member system (AMS) is a mixed electoral system under which most representatives are elected in single-member districts (SMDs), and the other "additional members" are elected to make the seat distribution in the chamber more proportional to the way votes are cast for party lists. It is distinct from parallel voting (also known as the supplementary member system) in that the "additional member" seats are awarded to parties taking into account seats won in SMDs (referred to as compensation or "top-up"), which is not done under parallel voting (a non-compensatory method).
Electoral systemAn electoral system or voting system is a set of rules that determine how elections and referendums are conducted and how their results are determined. Electoral systems are used in politics to elect governments, while non-political elections may take place in business, non-profit organisations and informal organisations. These rules govern all aspects of the voting process: when elections occur, who is allowed to vote, who can stand as a candidate, how ballots are marked and cast, how the ballots are counted, how votes translate into the election outcome, limits on campaign spending, and other factors that can affect the result.
Electoral thresholdThe electoral threshold, or election threshold, is the minimum share of all the votes cast that a candidate or political party requires to achieve before they become entitled to representation or additional seats in a legislature. This limit can operate in various ways, e.g. in party-list proportional representation systems where an electoral threshold requires that a party must receive a specified minimum percentage of votes (e.g. 5%), either nationally or in a particular electoral district, to obtain seats in the legislature.
First-past-the-post votingFirst-past-the-post voting (FPTP or FPP) is an electoral system wherein voters cast a vote for a single candidate, and the candidate with the most votes wins the election. Analogous systems for multi-winner contests are known as plurality block voting or "block voting" systems; both FPTP and block voting are "plurality" systems in that the winner needs only a plurality (the greatest number) of the votes and not an absolute majority (greater than half).
Electoral districtAn electoral district, also known as an election district, legislative district, voting district, constituency, riding, ward, division, or (election) precinct, is a subdivision of a larger state (a country, administrative region, or other polity) created to provide its population with representation in the larger state's legislative body. That body, or the state's constitution or a body established for that purpose, determines each district's boundaries and whether each will be represented by a single member or multiple members.
Parallel votingParallel voting is a type of mixed electoral system in which representatives are voted into a single chamber using two or more different systems, most often first-past-the-post voting (FPTP) with party-list proportional representation (PR). It is the most common form of mixed member majoritarian representation (MMM), which is why these terms are often used synonymously with each other. In some countries, parallel voting is known as the supplementary member (SM) system, while in academic literature it is sometimes called the superposition method within mixed systems.
Mixed electoral systemA mixed electoral system or mixed-member electoral system combines methods of majoritarian and proportional representation (PR). The majoritarian component is usually first-past-the-post voting (FPTP/SMP), whereas the proportional component is most often based on party-list PR. The results of the combination may be mixed-member proportional (MMP), where the overall results of the elections are proportional, or mixed-member majoritarian, in which case the overall results are semi-proportional, retaining disproportionalities from the majoritarian component.
BundestagThe Bundestag (ˈbʊndəstaːk, "Federal Diet") is the German federal parliament. It is the only federal representative body that is directly elected by the German people, comparable to the United States House of Representatives or the House of Commons of the United Kingdom. The Bundestag was established by Title III of the Basic Law for the Federal Republic of Germany (Grundgesetz, ˈɡʁʊntɡəˌzɛt͡s) in 1949 as one of the legislative bodies of Germany and thus it is the historical successor to the earlier Reichstag.
Scottish ParliamentThe Scottish Parliament (Pàrlamaid na h-Alba ˈphaːrɣl̪ɣəmɪtj nə ˈhal̪ɣapə; Scots Pairlament) is the devolved, unicameral legislature of Scotland. Located in the Holyrood area of the capital city, Edinburgh, it is frequently referred to by the metonym Holyrood. The Parliament is a democratically elected body comprising 129 members known as Members of the Scottish Parliament (MSPs), elected for five-year terms under the additional member system: 73 MSPs represent individual geographical constituencies elected by the plurality (first-past-the-post) system, while a further 56 are returned as list members from eight additional member regions.
Proportional representationProportional representation (PR) refers to a type of electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions (political parties) among voters. The essence of such systems is that all votes cast - or almost all votes cast - contribute to the result and are effectively used to help elect someone - not just a bare plurality or (exclusively) the majority - and that the system produces mixed, balanced representation reflecting how votes are cast.
