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Design 3
Learnability
Since this design takes most of the input from the receipt, it minimizes the input it requires from the user and thereby makes learning how to use it fairly easy. The different menus derive from similar known menus and therefore most smartphone users will find it very easy to use the interface.
Visibility
This design has pretty good visibility, it minimizes the number of editable options and buttons the user will need and the buttons that are included in the design are large and in the center of the screen. The different actions have appropriate affordances, and it is easy to find the relevant controls in every screen.
Efficacy
While this design increases user efficacy by automatically detecting most receipt's details on its own. Some other elements of the design, however, do compromises efficacy. The scan screen is shown before with only one option, forcing the user to make an unnecessary selection
Error Prevention
Error prevention is the biggest weakness of this design. Since it is highly automated, if the user errors in entering a receipt, or even if the system analyses the receipt wrongly, it would be very hard to recover from the error. The user have no easy way to override the fields.