In every election a percentage of votes cast are likely to be informal. Informal votes are ballot papers that have not been filled out correctly in accordance with the requirements of the Commonwealth Electoral Act 1918 (the Electoral Act) and instructions on the ballot paper, and can therefore not be included in the count of votes leading to the election result. Levels of informal voting can provide an indication of people's engagement with (and understanding of) the electoral process and, together with enrolment participation rates and measures of turnout, are therefore a key indicator of democratic health.
This paper provides a profile of informal voting at the 2010 House of Representatives election and presents results from the AEC's 2010 House of Representatives Informal Ballot Paper Survey. Statistics on informal voting at previous House of Representatives elections are also included to provide a historical context for the 2010 figures.
Analysis in this report includes discussion of proportions of informal votes and informality rates. Proportions of informal votes use the relevant total number of informal votes as the denominator, and are shown to one decimal place. Informality rates (proportions of total votes cast) use the relevant total number of votes cast as the denominator and are shown to two decimal places.
It should be noted that some figures relating to informal voting at previous elections have been revised to correct errors or inconsistencies in previously published reports. Footnotes have been added to tables to indicate where revisions have been applied. These revisions do not impact on any of the key findings made in previous reports.
In addition, changes to electorate boundaries as a result of redistributions will affect the comparability of data between elections.
Two main sources of data were used to analyse informal voting at the 2010 House of Representatives election. These were: