At the Kansas Meadowlark, Earl Glynn has an article that illustrates some of the difficulties that researches face when working with voter data. I haven’t done nearly as much of this as Earl has, but I can tell you there have been times when I’ve been quite frustrated with voter data that I’ve received. I’ve had to spend time manipulating data in order to get it into useful formats.
The Meadowlark story is Comparing Voter Registration to Nov. ‘08 Ballots in Allen County. Too Difficult?