Definitions of terms: Ballots - Ballots are the papers on which votes are recorded. A vote can be a single mark, or one or more marks or numbers to elect one or more candidates. At some elections, voters could mark ballots with more than one vote, giving the result that there were more votes cast than voters. This was the case for elections for the South Australian House of Assembly until 1927. Turnout - The turnout at at election is the proportion of voters on the electoral roll (registered voters) who cast a vote. In this database, turnout is measured as the rate of voting in contested seats, shown as a percentage of registered voters; see also compulsory voting. Electoral district - Electoral districts are also called electorates but, as the term electorate also refers to the whole body of voters across a political system, the term electoral district has been used in this database to keep the distinction clear. Electoral roll - The electoral roll is the list of voters who are registered to vote at an election. Compulsory preferences - a requirement that a voter must rank all candidates on the ballot paper under a system of preferential voting. Contingent voting - This can be thought of as a form of preferential voting (AV) with compulsory or optional preferences which permits the voter to vote for one or two candidates, but no more than two, by indicating a first choice candidate and, if the voter wishes, a second choice candidate. If a candidate gains more than 50 percent of the first preference votes cast in an electoral district, he or she is declared elected. If there is no such candidate, the second preferences shown on the ballot papers of all but the two candidates with the most first preference votes are divided between the top two candidates. After this assignment, the candidate with the most votes is declared the winner. This system has been used in general elections for the Queensland Legislative Assembly from 1893 until 1941 (in single and multimember districts until 1909), and for the New South Wales Legislative Assembly in 1928. It was also used for the first direct election of the Mayor of London in 2000 where it was called supplementary voting. For a discussion of contingent voting, see David M Farrell and Ian McAllister, The Australian Electoral System: Origins, Variations and Consequences, pp 25, 52-54 (Sydney: University of New South Wales Press, 2006, ISBN 0868408581). Electoral system - The electoral system is the set of rules which specifies how elections are organized and how votes are cast and counted at an election. The broad category of electoral system used to elect members at an election is shown in the database, and the entries are indexed in this database under the name of each electoral system. Australia has been adventurous in its experimentation with electoral rules and electoral law. It is planned to add more information on Australian electoral rules to the database. First past the post - A first past the post electoral system is one in which a voter is required to mark the ballot paper, usually with a cross or tick, indicating the voter's preferred candidate. The winning candidate is the one with the most votes. In electoral contests where there are only two candidates, the candidate with the most votes will have a majority (that is, more than 50 percent of the votes cast). If there are more than two candidates, the candidate with the most votes may only have a plurality (that is, more than any other candidate, but less that 50 percent of the votes cast). For this reason, first past the post voting is sometimes called plurality voting and is indicated in this database as 'first past the post (plurality) voting'. First past the post electoral systems were widely used in Australia until the rise of the Australian Labor Party prompted anti-Labor parties after 1910 to adopt preferential voting for most lower house elections in Australia. First past the post electoral systems are usually associated with single member districts, but they can also be used in multimember districts. The use of plurality voting with multimember districts is often called 'block voting'; the voter is given as many votes as there are candidates to be elected from the district. Such a system favours well organized party tickets and a successful party can win all the seats in a multimember district with a plurality of votes. This system was used for the Commonwealth Senate until 1919. Plurality voting can also be used in multimember districts by giving the voters as many ballots as there are candidates to be elected from the district. This enables voters to vote for several candidates or to cast more than one ballot for their favoured candidate (see also ballots). first preference vote - Preferential voting requires a voter to rank candidates on the ballot paper in the order of the voter's choice. A voter's most preferred candidate is the one against whose name the voter has written '1' on the ballot paper. This candidate represents the voter's first preference vote. This definition also applies to voting under systems of proportional representation. Where a first past the post (plurality) electoral system is used, the first preference vote refers to the number of ticks or crosses gained by each candidate. Change from previous election (Swing) The change in first preference vote won by a party at a given election when compared with the previous election, expressed as the difference between the percentage first preference vote shares. Note that the party must be listed in the database for both elections (see listed party) for a figure to appear in the column. If the party was a listed party in the previous election but ran candidates under a difference name, no figure for changed vote share will appear (see party name). Turnout - The turnout at at election is the proportion of voters on the electoral roll (registered voters) who cast a vote. In this database, turnout is measured as the rate of voting in contested seats, shown as a percentage of registered voters. Registration of voters - Registration (enrolment) as a voter is now compulsory for all Australian parliamentary elections (note the partial exception of South Australia, below). With minor qualifications for length of residence and variations for some state and territory elections, all eligible Australian citizens are required to be registered as voters. Comprehensive voter registration can be achieved by surveying households, and by requiring state agencies which compile lists of names and addresses to provided these lists to electoral authorities. For commentary on the context of compulsory registration, see David M Farrell and Ian McAllister, The Australian Electoral System: Origins, Variations and Consequences, pp 121-124 (Sydney: University of New South Wales Press, 2006, ISBN 0868408581). Election dates are: 9 April 1890, 14 April 1893, 25 April 1896, 29 april 1899, 3 May 1902, 27 May 1905, 3 November 1906, 2 April 1910, 10 February 1912, 27 March 1915, 5 April 1918, 9 April 1921, 5 April 1924, 26 March 1927, 5 April 1930, 8 April 1933, 19 March 1938, 29 March 1941, 29 April 1944, 8 March 1947, 4 March 1950, 7 March 1953, 3 March 1956, 7 March 1959, 3 March 1962, 6 March 1965, 2 March 1968, 30 May 1970, 10 March 1973, 12 July 1975, 17 September 1977, 15 September 1979, 6 November 1982, 7 December 1985, 25 November 1989, 11 December 1993, 11 October 1997, 9 February 2002, 18 March 2006.