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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 -
Good: Searching for contacts and autocomplete box helps user invite people efficiently. Also the Scrollable selector for the dates is more efficient than traditional text input methods. For users who want to link their mashcal to their calendars like gcal "Linking calendar" option is available. They can also import contacts from other contacts lists. Additionally, history of previous events which would be incorporated to inviting people window will allow people to choose invitees from the list of previously invited people, making it efficient to reinvite people.
Bad: Due to the limited screen size of phone, the time slow selection can not show all the time slot in one window. A user has to scroll down and make a selection if he wants to choose 8pm for example.
Safety-
Good: The fact that things are selectable with a one single touch makes it easy to recover from errors. Say a user choose a wrong time slot when picking a date. she can then just simply press on that time slot again to unselect. Another thing that helps with safety is that the autocomplete in the search box. The user can easily select invitees from the list. The history features which would be incorporated to inviting people window will allow people to choose invitees from the list of previously invited people. Therefore, reinviting people to an event is almost error-free.
Other-
We can play with Typography ( different fonts, sizes etc.) to solve the problem of not being able to see many time slots in one window. The use of green for available slot ( red for unavailale ) will help user easily pick the appropriate dates.
Design 2
Storyboard
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