One of the interesting features that you find with Windows Phone 7 devices is the addition of the Back and Search buttons to the Home button area.
My first impression of this choice was not a good one. Users would need to learn to depend on the Home row buttons and wouldn’t see any buttons within the bounds of the current app itself. And depending on the specific device, the hardware buttons may be pressed accidentally which could cause confusion for the user.
It appears I was not crazy as both of the issues came to light in public forums after release.
It is a new concept and users need to be helped to see how it works and to start depending on it. The good news is that the whole OS works this way so it shouldn’t take too long before the design feels right to the user. After using the device myself for awhile, it actually becomes a nice familiar safety button I can use to get of different screens.
The only time I seem to trip on it still is when I back out of the app on accident. This normally happens when I press the button too many times in a row or when i forget what the Home screen of the app looks like.
But App developers will prevail in this world of Back button singularity!
Here’s how the Facebook app deals with the Home screen/Back button/kill my app issue.
They’ve added a warning dialog, that can be turned off when the user feels comfortable with the behavior.
Although the accidentally backing out of the Home screen is the most destructive because it kills the app, which means you then have to sit through the app loading again which on WP7 is almost always noticable (can’t wait for the update!), cancelling a screen can still be an issue.
Users are used to the seeing a cancel or Back button and some app developers still add them into their screens. This may go away eventually, but at this point most 3rd party app developers don’t feel like footing the education bill. You’ll notice that even in the Outlook New Mail screen there is an “X” button to cancel the New Mail creation.
Overall the important part when designing your WP7 apps is to remember the Back button guidance so your app behaves like users expect:
- Pressing the Back button from the first screen of an app must exit the app.
- Pressing the Back button must return the application to the previous page.
- Pressing the Back button in a game should only be used to pause and exit.
- If the current page displays a context menu or a dialog box, pressing the Back button must close the menu or dialog box and cancel navigation to the previous page.
- The Back Button should first close the SIP keyboard if it is visible.
- You should only implement Back button behaviors that navigate back or dismiss context menus or modal dialog boxes. All other implementations are prohibited.
Finally only break the guidance when you feel like you really need to, and then hope you still make it through the submission process. ←