...
Efficiency
dd
Error Prevention
dd
Learnability
Buttons that allow users to perform actions on a bill (edit, pay, etc.) are clearly labeled and placed next to the listing for that bill. Links to other pages on the site are displayed prominently in the taskbar.
Visibility
Information about users and households is visible in sidebar. The other pages the user can view (user details, calendar, etc.) are listed in the taskbar at the top of the page. On the pages that list bills and show how much money the user owes, lines of data can be expanded to show further details, but by default they are collapsed to maintain visual simplicity. Clickable links are underlined; the user's current page is highlighted in the taskbar.
Efficiency
Users can find a bill from the user page, the bill listing page, or the calendar.
Error Prevention
Not great. Does not allow user to undo transactions, although before a transaction goes through the user must review a confirmation page.