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Good: Couple of affordances are used in the interface to improve usability. Traditional affordances like arrows and buttons are natural to the user. Their behavior is consistent with way people think about them. The "Percentage of People RSVP-d " * * icon communicates whether the event was for a group or just for Jack by showing many human figures or just one. That icon is filled up according to how many people reply to the invitations. The thumb icon on the Pick Date window on Figure 3 tells the user that the time slot can be selected with a touch. Without those ; this communicates the model of the interface to the user effectively. Another thing that helps with the usability is that everything that user can interact with is labeled accordingly. Therefore, a user will not be wondering which part of the interface corresponds to what task. 

Bad: The Pick Date interface might be initially unfamiliar to users.  2 or 3 slide walk through to show how to select dates and time slots might be necessary.

Efficiency -  

Design 2

Storyboard

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