Why let voters control you when you can control voters?
Types of control.
source London Metro 21/03/2012
Essentially moving the goalposts, this is when the electoral boundaries are drawn in such a way as to produce a certain result. This could mean grouping certain demographic groups within one voting area.
Violence and threats of violence can often beused to pressure results of an election. But it could also be economic threats ,such as an employer dictating which way their workforce should vote.
Simple but effective, and used in many countries. In Thailand, 30% of household heads said they were offered payment during the 1996 elections
This is when someone votes multiple times. In some countries 'election ink' - a semi permanent dye - is used to help spot someone who has already voted
Often involves higher levels of corruption. For example, officials could remove someone by 'mistake' from the electoral roll. Other rechniques could be used to inconvenience certain voting groups, such as holding an election on a holy day.
This is a rare form of fraud as electronic voting machines are difficult to access.
However there is potential for someone to corrupt the software to favour a candidate.