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• One-click process: Because the system advances as soon as any option is clicked, the user can proceed quickly without needing to select an option and then press next. One click per page is much faster than two.
• Minimal text: The screen has minimal text, so it is easy for the user to scan the text and find the right option. This reduces the mental processing time required.Lack of full-ballot view: After entering the vote for a given race on a specific ballot, that same box will not come up again unless the user chooses to go back. This means that the user can keep going and doesn't have to take time for summary or double-checking
• Ballot summary: The user has to stop and review/skim each ballot before submitting it and moving on. While this decreases efficiency, it was necessary for safety (see below).

Learnability:

• Item selection: Because only one item shows up at a time, the user will quickly learn to just click the appropriate name and that the system will move on. Much of the changing between screens is done automatically, minimizing the need for users to learn system navigation.
• Minimal text: Because there is very little text on each screen, the user has very few choices what to do. This makes it easy to quickly determine the right action to take.
• Unclear buttons: As drawn, the users who are unfamiliar with computers may not understand that each candidate's name is a button. This is a problem with learnability particularly for our user class of older, non-tech-savy auditors. 

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• One-click Process: Because the system advances on any click, the user doesn’t have a chance to verify that they selected the correct option, reducing the safety.
• Large Buttons: The buttons are all large, so the likelihood of accidentally clicking the wrong button will be smaller. Users will also see the button depress when clicked, so they will get that feedback about which element has been selected. These together improve the safety.
• Forward/Back Buttons: If the user makes a mistake, she can chose the back button to correct it. Error correction improves safety. The forward buttons let her navigate back to her current position without reentering information – which would increase the likelihood of making another error.
• Status Bar: The user can keep track of how far she is.If a ballot was missed or double-submitted, this mechanism will help catch that error. For example, if the user sees that she is entering the 3rd ballot, but the ballot number is 2, she knows that one of the ballots was not properly submitted.
• No Ballot summary/confirmation page: Aside from the button depressing at the user 's click and the ballot number incrementing, the user gets no feedback. Hence, if she makes a mistake it will be hard to spot and realize this. We are considering adding a ballot summary screen at the end of each full ballot. This would reduce efficiency point #3, but would improve safety enough to make it a considerationhas the opportunity to view a summary of each ballot and make sure it is correct. This is especially important because when entering the information, there is very little feedback. So having this summary greatly increases safety and the likelihood a user will catch any errors.

Storyboard 2 – Ballot metaphor

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