Touch Screen Usability: Election Edition!

Ah, election season. Here in the U.S., early voting has already started. In one state, nearly 20% of registered voters had already voted by Monday. But all is not well in the land of democracy. Or the Republic. Or whatever.

Terrified by the hanging chad paper ballots of the 2000 elections, many states went to electronic, touch-screen voting machines. Ignoring the myriad security issues, let's talk user experience. First, please note that the usability community has had a formal voting usability project since 2001. It's frustrating to watch new machines come out and ignore established security and usability freely available standards. (Some have gone back to paper, with scanners to quickly read the votes. Paper is an interaction method, and one that's pretty well understood; good or bad design can happen in any media.)

We have three key constituents here: election officials, poll workers, and voters.

Many poll workers are essentially volunteering. When I did this in California, I was paid something less than minimum wage, though this was 18 years ago. It's social: neighbors come in and announce that they are here to cancel out each others' votes. You see people you don't normally see. It's a great way for a retiree to spend a day.

Please note I said nothing about "technical" or "computer savvy". So, issue number one is training the poll workers on how to help voters and manage the machines. This problem is pervasive for most interactive voting machines. I've not seen any problems with the fill-in-the-bubble paper votes with on-site scanners in my precinct. Another benefit of the scanner system: you only need one machine for 1-2 precincts, as it only takes 10 seconds to do the computer part of the process.

Now the voters themselves. Hopefully, you've got all walks of society voting, from semi-literate computer novices to folks like typical readers of this blog. All need to be able to vote. Fortunately, there's lots of help, but voters are going to feel somewhat pressured to move quickly. This is especially a problem where states do not send out sample ballots, so voters are seeing the layout for the first time.

Touch screen kiosks are easy to set up and perceived as easy to use. After all, touching is "natural". Unfortunately, it's not that simple. One early voter in Decatur, Tennessee had the voting machine "switch his vote" from one candidate to the other, and was told "the error sometimes occurs when a person??s finger touches close to the line of the box the candidate??s name is in".

Ah, parallax. A problem with touch screens, particularly with kiosk. The touch surface and the display surface are not the same, so what is being touched does not necessarily match what the machine thinks is being touched. The two have to be aligned, but the person doing the aligning has a particular point of view that doesn't necessarily match the voters. And the things can lose alignment over the course of the day.

Too bad the developers did not follow simple kiosk design guidelines. For example, check out SAP's Interaction Design Guide for Touchscreen Applications (Experimental). Don't use it for mobile web design, as you'll have to do a lot of analysis to make it work for that environment, but it is precisely written for kiosk design. And if you read it, a some simple heuristics valid for most touch interaction emerge:

1. The touchable area of a control and its visual representation need not be the same size. That is, the target can be larger or smaller than the graphic.
2. For most situations, provide a separation of at least 3 mm between targets. If a touch does not fall in the target area, do nothing. The user will tap again.
3. The graphic should generally be larger than the target. Ideally, the graphics are also separated.
4. Use large graphics for buttons, around 2 cm square.
5. Provide immediate feedback for the action, such as changing the visual state of the actual control. Bonus: change the label to add a checkmark or some other natural visual.

Excellent resources:

• Touch Usability blog and the voting problems entry
• Usability Professionals Association Voting and Usability project
• Voltage blog best practices of touch screen design

And of course election officials sure can write their requirements to address real needs of voters. Since they seem to use the "requirements" put forth by manufacturers, instead of those independent groups above, probably the best way to change this is to get people who care, and usability professionals best of all, onto the election boards. We're all too busy around here, but please, you should go help out.

Of course, the ballot marking is just a part of the system. Even just taking the polling place into consideration, there is traffic control and flow, paperwork, queuing, interfaces and backlogs on other machinery (e.g. making smartcards for the kiosks), etc. Or, how about if there is a problem with the machines, like the Diebold timeout issue? See the image at the top of this post for a too-wordy potentially untruthful "solution" to help voters. I say the answer is not to 1) lie about the reason, 2) give an excessively-wordy notice out, 3) on small paper, and 4) then take it away from voters before they actually get to see the machine (Steven snuck one out, though).

If this is all too heavy, and you are tired of voting news, try this take on the real value interactive maps add to the TV news. The relevant bit starts about 5:30 in.

This is one of the cases where good old mechanical buttons on the side of the screen would work best.

Agreed.