A dorothy dixer is a question a member of parliament asks his own party. The tactic is mostly used by the party in government. There are two purposes to this. One is to use up Question Time and hence limit the damage the Opposition might be able to do by asking probing questions without notice. The other is to provide a platform for government agenda-setting. Hence a dorothy dixer must grammatically be a question so it is allowable in Question Time, but is functionally not.
Q - Would the Minister kindly inform the House as to progress in reducing interest rates since November 2007?
A - I thank the Honourable member for his question and can say that I am delighted to speak to this very important issue. Since this government was elected in November 2007 blah blah blah ...