Maryland's recent decision to dump touch-screen voting machines in favor of a paper ballot system could come back to haunt voters, said the lead researcher on a study of voting technology.

The new report found that while every voting system tested had flaws, touch-screen machines — which Maryland uses — met the top criteria of the study: They were the most user-friendly.

Paul Herrnson, the study's principal investigator and a University of Maryland professor, said that in light of the report, Maryland's choice to change from touch-screen machines to an optical-scan system is ill-advised.

"In terms of improving the voting process, I think it's a mistake, and there's a lot of evidence to speak to that effect," Herrnson said. "The most common voting error that we found is actually voting for the wrong candidate by mistake," a phenomenon he said is easier detected with touch-screen systems that show voters all their choices before finishing the ballots.

The five-year study focused exclusively on the issue of usability by conducting field studies, soliciting expert reviews and laboratory tests comparing five current voting systems and one prototype, including three different kinds of touch-screen systems and an optical scan system. Researchers from the University of Maryland, the University of Rochester and the University of Michigan participated in the study.

Maryland plans to start using optical scan machines costing about $20 million in 2010. However the Maryland State Board of Elections will still be paying for the $65 million touch-screen machines until 2014.

Robert Ferraro, co-director of Maryland-based SAVE our Votes, said he doesn't have faith in the current, entirely computer-based, touch-screen system.

"You can't trust any computer, you know," Ferraro said. "When you vote on these touch-screen machines, you absolutely, positively, in no way have any idea how your vote is being recorded, because nobody can see inside the machine how the vote is being recorded."

Ferraro said he's glad the state is moving to a system that has a back-up paper record, something current machines lack. With the state's new optical scan system, voters mark next to their selections on the ballot with a pen or pencil, similar to Scantron forms used in multiple-choice tests.

"With Maryland's electronic system, it can't be audited, because there's no independent record to check, there's only the computer memory and that's it," he said. "But with an optical scan system, you have the paper ballots, and you have the computer tally, and you can check the computer tally independently by hand and see if the computer tally was accurate."

However, Ross Goldstein, deputy state administrator of the board of elections, said he believed the touch-screen system was successful in Maryland.

"It's been very successful, we've not lost any votes on it, it's never been compromised, and in that respect it speaks for itself," he said. "We had a lot of confidence in the original system, but with that being said, paper adds something to the process that many people wanted."

The state board paid for part of the study, along with the National Science Foundation and Carnegie Foundation. The voting machines were donated by their manufacturers and developers.

Pete Sepp, vice president of communications for the National Taxpayers Union, and a Maryland resident, was disappointed in the move.

"This is a particularly galling example of government failing to look before it leaps before investing in new technology," Sepp said. "These findings (from the Maryland-led study) ought to give them pause to go back and think about this. At the very least, the state ought to reconsider its decision to outfit a new voting system — we've already made one mistake."

Maryland Sen. Thomas V. Mike Miller Jr., D-Calvert, said the primary impetus behind switching machines was groups like Ferraro's SAVE Our Votes, which is working for secure, accessible, verifiable elections in Maryland.

"I personally like the touch screen machines, we paid a lot of money for them and we haven't finished paying for them," Miller said. "To appease these very concerned citizens we're going to be spending a lot of money and the governor thinks it's worthwhile, so we'll be moving in that direction."

Herrnson agrees with Sepp that in the end, the switch is probably a fiscally unwise one.

"I think it will make a small activist constituency very happy, some voters will look at it as a step backward, and in the end it will be an expenditure of funds that have been could much better spent elsewhere."

Capital News Service contributed to this report.