This analysis represents an early research effort by the Australian Electoral Commission to examine trends within categories of informality. The analysis of the informality at the Werriwa by-election confirms a major finding in previous reports on informality in Australian House of Representatives Elections. Namely, that a very strong predictor of a rise in informality is an increase in the number of candidates on the ballot paper. 
This research also supports the argument that as long as there is a differential electoral system between the Senate and the House of Representatives, some level of informality will exist. This may be compounded by 'How to Vote Card' cards and the order the elector completes the two ballot papers in.
The analysis of the by-election also revealed that the level of informality might increase when a candidate from a major political party does not contest a seat in an election.
In Research Report Number 7 – Analysis of the Informal Voting During the 2004 House of Representatives Election, concerns were expressed at the proximity of the NSW and QLD State elections compared to the next federal election. The research stated that if stakeholders do not address the impact of optional preferential voting in these 2 States, the informality levels were likely to remain high. This research suggests that for States with optional preferential voting, the further away a federal election is from the State election, the less chance there is of a voter marking 'Number 1' only on the ballot paper. This research also notes that the absence of a Senate election at by-elections may impact on the reduction of the informal category – 'Number 1' only.
The AEC and its stakeholders need to address the impact of "how to vote" cards, and optional preferential voting in New South Wales and Queensland, or informality is likely to remain high at federal elections.
The AEC will undertake analysis of informality at future events in order to identify any trends or interpretation on a national, state/territory, and divisional level. The results of future analysis will assist the AEC with the development of targeted public awareness campaigns.